Have you seen or tried Gumroad?
It’s an incredibly-simple way to sell almost anything. The interface is beautiful and intuitive and setting up shop is one of the easiest and most-pleasant experiences I’ve ever had.
In fact, I was planning on migrating to their system for my eBooks until I retired them all recently. Look at these screenshots of the entire back-end and front-end experience to get an idea of how it works:
They accept credit cards and even have a developer API for those that want to customize on top of it if you want to get all crazy.
Incredible system – it’s that good it makes me want to think of a reason to use it.