Appearances are important One of the most important things, I think, is the look of what you have to offer. For example, my CD comes in a cool diecut case , if I say so myself, which attracts people on the first glance, even before the music does. In fact, I know many people who've bought the CD purely for the case, disliking the music. I think this is the best way to sell stuff when people have no clue about what your music is, and have never heard of you. I don't think price is that important when convincing people to buy stuff, but I can't say it hasn't helped.
People are more willing to take risks if the cost is lower.
Your mileage might vary. I personally feel CD prices are exorbitant, and I refuse to play that game, and I also believe that if I wanted to make a lot of money selling CDs, I should sell a lot of CDs, not price gouge, as some people have seen fit to do. A related item is how you accept orders. Some the tricks to keep in mind here including sending a professional looking invoice along with the order, and providing a return envelope for people to mail the checks to. I'm sure accepting credit cards could only be nothing but beneficial.