Depends on your definition of 'non-profit' and how that influences your thought of reasonably priced. I see that term refer to three very different entities: 1) Organizations who are basically large businesses that have a "not-for-profit" status accorded to them by the IRS (NY Presbyterian Hospital) 2) Organizations that are donor-based or membership-driven and very successful (United Way, Red Cross) 3) Organizations that are donation-based and run on a budget between "small business" and shoestring

I'm guessing you're asking about #3 and likely on the shoestring side, which really means you're looking for a free or very low-cost solution. And I don't know good answers to that. (If you're not on a shoestring, then Blackbaud makes the industry-standard software).

I have built custom-software for several non-profits. Requirements are somewhat similar but most organizations prefer to have their own customizations (a chamber music non-profit wants to keep track of ticket sales in addition to donors; the head of a children's performing arts org doesn't isn't tech savvy enough to understand the default interface; everyone wants custom reports).

I'm not interested in working in that market again for the foreseeable future, so this is not a pitch. I've charged between $5K and $10K for a custom solution and $200 per user annually for maintenance. Some non-profits have approached me and blanched at the cost. Depending on your goals, I can make a business case for the expense (though now I'd say Blackbaud might be a better choice than custom).

The last time I did the research was 3 years ago, and there could be a reasonable web-based package out there for $50/user per month. Some may charge per donor ($100 per 500 donors per month or something). If those prices are out of your range, then you're probably stuck.