The most important question you've asked here is:

"Should I care more about making money or doing something that I have a "passion" for?"

And my answer is: You should care about both, approximately equally.

I would advise that you don't ever choose something that makes you want to gouge your eyes out with a metal fork just because the average yearly salary is six or seven figures. Most likely the result will not be anything like what you are visualizing (eg. early retirement, actually having time to enjoy your money, reasonable mental and physical health...) . I suspect this kind of choice tends to lead either to dropping out of your major, and thus losing both time and money, or to far too much agony when you do enter the workforce. The more interest and enjoyment you get from your chosen field, the better. In a similar vein, be wary of fields that sound cool or tolerable if you have very little idea of what the work in them is actually like. If you have some familiarity with doing whatever is done in your chosen field, that helps a lot. I majored in Computer Science, but I had been programming as a hobby for many years before that, so I already kind of knew how I felt about it. I knew about the frustrating parts, but also knew that overall I enjoy it immensely. I would definitely recommend considering which hobbies you enjoy most when you think about what you want to major in.

On the other hand, I would not ignore the importance of money. Please consider: how much would you like to have the independence to make your own decisions, because your money is your own? For me, this was very important, so I was unwilling to go into a field where the average (the mode, not the mean or median) salary was small, or where money seemed to be very unreliably distributed. For example, some fields have a few very prominent successes who make crazy amounts of money and a large number of talented, hardworking individuals who make almost nothing. Do not assume you will be one of the few prominent successes, regardless of your talent or ability to work hard. Also consider how important financial security is to you. Even if you are well off now, circumstances can change. So try to choose something where you will be able to put some of your money aside into savings (I think the amounts most people advise for this always sound a bit low...). When I was younger, there were times that money was extremely tight for my family--I knew that wasn't how I wanted to live once I was an adult, because it always felt so financially insecure. On the other hand, some people thrive on very little money, so you will need to consider how much your temperament matches mine. This is not to say I didn't take great pride in spending as little money as possible--but this was largely because I wanted the number in my savings account to be as large as possible. Because I did take this into consideration, I don't currently have to worry about money or debt, which is rather nice.

So, that's my advice. Hope you found that helpful in some way. It did at least work for me. I have a career that I can actually enjoy doing, and I don't have to live in poverty.

A weblog called StudyHacks has articles about passion that I think you would find interesting.

Specifically The Passion Trap and The Danger of Dream Job Delusion.

EDIT: FORMATTING

Don't try to predict the future. Read Taleb's "the Black Swan". Instead, try to prepare for an uncertain future by learning generally useful skills that will be helpful in many possible futures. Along these lines, I've decided that I'm going to get a double major in statistics and computer science (particularly something related data mining).

Advantages:

1. Generally useful. Statistics is used in a lot of fields.
2. Impact- So many studies are poorly designed and so the results are useless.
3. Comparative advantage to people with a LW mentality- I think that few people will know about Judea Pearl's "Causality" or Jaynes.
4. Cool Shit! Google's driverless car. Machines that write jokes. Siri. the movie "moneyball"
5. Make DINERO!!! See Moneyball. See wall street algorithms that make most of the trades these days. See the gambling industry.
6. Understand the world. Intellectual stimulation.

I'm also self-studying psychology. If you can understand statistics, psychology, and philosophy, you will have a very solid understanding of the world around you.

http://bits.blogs.nytimes.com/2012/01/26/what-are-the-odds-that-stats-would-get-this-popular/

I always advise in favor of a double major with one major being something sciencey and quantitative (math, natural science, engineering, computer science, et cetera) and the other being something you care about. If those categories overlap, then you have less work to do.

After perusing advice from the comments and checking the details of the majors I listed above, the ones that seem to promise the most utility would be CompSci, Math/Mathematical Sciences, or "Economics and Mathematics/Statistics" (a single joined major, not a double major). I'm not particularly drawn to software design, so CS is an option I'd put on the backburner at this point. MathSci is a combination of CS, stats, and math; either that, or econ/stats or econ/math I think could open doors to good salaried employment (i.e., actuary, accountant, finance, various businesses(?), etc.). It would be easy to double major in one of those with HPS, or a minor in philosophy, which are flexible, and I can take cool courses like this. Studying neuroeconomics would be interesting grad work; this is motivating me to consider taking more psych/neuroscience.

On VC entrepeunership: to quote christina,

some fields have a few very prominent successes who make crazy amounts of money and a large number of talented, hardworking individuals who make almost nothing. Do not assume you will be one of the few prominent successes, regardless of your talent or ability to work hard.

Not to begrudge those of you aiming for VC success, but I don't personally see myself as the ambitious kind who takes risks with my brilliant idea and succeeds in such a field. At least, not without some collaborators, which would hardly make it my business anyways. I consider questions posed on 80000 hours about career choice and utility too, but those are separate questions I'm not prepared to answer quite yet.

Thanks for the links from Study Hacks and other sites. I'm confident enough in my skills to have a life outside of a career so that my career won't define my life, unless I happen to fall into a really fun career anyways.

We can say with reasonable confidence that internet access to information and training will stay as good as it is now or more likely vastly improve in the future. As such there is very little value to learning large amounts of information or specific skills, instead you should look for courses that give you good transferable skills, and learn other things as needed.

Personally, [with standard disclaimer against generalising from one example] I've found studying philosophy extremely good in those respects. It contains a lot of the general rationality and thinking skills we discuss on Less wrong, and a chance to practice them beyond understanding in theory. And once you have the ability to rationally assess arguments and draw out the best parts it becomes exponentially easier to learn and do well in other subjects. A good department will also emphasise clear writing and presenting your arguments persuasively. Given your stated interest in mathematics and compsci Formal Logic might be particularly god for you.

"Smart people tend to clump together, and if you can find such a clump, it's probably worthwhile to join it. But it's not straightforward to find these, because there is a lot of faking going on." P. Graham

In every field exist crackpots, but in hard science they are more difficult to find.

LW community is full of CS guys, then is natural to suggest the area. So do i. You will be a programmer sooner or later. Choose something that do math part of the time, because you need math thinking on pratically every serious subject.

In addition, everything is digital, the future is emulation. It's vague, but resume the aspirations of technological market. If you don't like the private sector, go to academia. Try to be precise, do research, and if you are not so good at math, go to business again. Avoid idealism.

Maybe you like frogs, but don't forget existential risks. A little help in a crucial question is more important than a great effort in something lateral.

Find your predispositions.

I'd suggest double majoring if at all possible, this will help keep you options open. Of course at most schools this will reduce the amount of elective classes you can take, but the end result is probably worth it. If you can find two subjects that add value to each other, but have different core markets(eg. CS & PSCY with a intent of going into HCI) thats a nice plus.