That's way too much to ask of SVTP to offer an escrow service.
Yup, now that's a good idea.
I'm a member on 3si.org, they have a system where the admins verify all your personal information before you're allowed to create threads in the classified sections. Then again they have a MUCH smaller user base, doing the same on SVTP could become tedious.
3000GT/Stealth International Message Center - Announcements in Forum : Classifieds
You would just have to add a few mods in the market section to fill that void.