I was looking through the demo and found a number of themes there that people have tried selling in the FP market place. Always thought it was a bit dodgy seeing as those selling them didn't have much coding experience.
I'd imagine you're allowed to sell them, but you never know...you might end up running into someone else who's got the same program. :shrug:
@Murder he Wrote
You can sell them as long as you buy the better license, which most everyone does, and as long as your don't include any original stock photos in the finial (for headers and stuff). The images it generates are fine to resell.
It's funny because themes created with it are actually better than some hand-coded themes. For example my "Rune Sucks" site was created with it 😉