Due to your level, there will always be the issue of trusting your shop (if ever you go with this idea), so you should acquire one of the known escrow providers (OgNasty for instance) to help you make it happen. There's already few (good ones) shops that have been doing what your trying to do for some time and the only way if your going to be successful is, if your going to offer something that none of them offer, perhaps something like purchase rewards that could be added to their account and used on their next purchase and etc... Regardless of what I said, it will always be good to have another competition for those out there and could surely make all of them improve in the long run too.
He didn't specify if he wanted to do this on the forum, if OP starts his own website, which is most likely I think, it would be pretty strange to offer escrow.
Maybe not for the first few purchases, but have you ever seen a web-shop that offers escrow?
