This is great. I would love a nicer home page for http://www.sharelatex.com. I looked at ones on theme forest but didn't want one framework for my homepage and one for everything else. Will defiantly look at what comes up there.
On stealing the css: your market are people who know the effort it takes to build something and are probably likely to pay $15-$50 for a big time saver.
I hope to get some more sellers on board soon so there's more to offer. I'm glad most everyone seems to feel the same way about stealing the live previews. There is honor out there.
I've not looked properly but future suport is quite important. I have been upgrading to bootstrap 2.0 and there are a lot of breaking changes, having future versions available would be something I would want to see, even if it requires and upgrade fee.
Upgrading from 1.4.0 to 2.0.0 was kind of a pain. I definitely am on the same page as you. Sellers attach a version number (of their own invention) to the items they upload. When a seller comes up with an update to their item they would upload it and update the version. At which point anyway who has purchased it in the past would be able to upgrade for free. (I don't like the idea of buying a theme and then paying to get the latest changes.)
On stealing the css: your market are people who know the effort it takes to build something and are probably likely to pay $15-$50 for a big time saver.