You can (and probably should) use a merchant clearing service to handle credit cards. Otherwise fraud will eat you alive. The cost per transaction is high IIRC, but the alternative is worse. You sales will be small unless you take credit carss. There are few cases where I'm willing to go to the effort to get a money order and wait, particularly if I got the item by download. It just encourages cracking in my opinion. You could do something like only provide the item on a CDROM, but the cost of handeling that is high if your time is worth much. All things considered, I would suggest using Renderosity (or some other existing store) to start and see if you have something people will really pay for. The amount of labor involved in setting up a merchant site is very significant. You need to sell a lot of $10 textures (or whatever) to make up for 80 hours of time testing, coding, talking to the ISP, negotiating with the credit card service, arguing with tech support, etc. Just my opinion.