Joel Spolsky has written a great article about how pricing works, and all the different things that need to be taken into account when setting the price of your product.
Sort of.
You see, every time you think you understand how it works, he pulls the rug out from under you with fascinating insights into human behaviour and corporate stupidity.
Still, by reading this article you'll have a good appreciation of the theory of cost curves, consumer surplus, coupons and discounting, and home/professional/enterprise editions of software products. You'll understand what companies are trying to do when they come up with strange-looking pricing structures and cash-back rebates, and with luck you'll be able to figure out how to avoid letting them rip you off.
Or you'll just conclude that it's all too hard and let somebody else deal with setting prices.
Joel on Software - Camels and Rubber Duckies