Are you in a position where you can convert your time to money freely as-desired?

I expect that people on Less Wrong are demographically more likely than most to be able to do this, but most people have jobs which take up a certain amount of their time, beyond which they are not at liberty to convert more time into more money at a comparable rate should they so choose. So time/money tradeoffs which fail to account for whether the time being traded off is actually employment time, and thus valuable at that rate, will tend to be misleading.

Edit: I missed the fact that gjm has already noted this in another comment.