Yeah, but still - it would be more reasonable to create a sales system that is a natural part of vBulletin rather than integrate something buggy (I could list dizebs of bugs right now, but I am sure you are aware of some yourself) that wouldn't allow much of interaction anyway. I have integrated my copy of PHPAudit into vBulletin, but only to a certain extent - more advanced things are not possible to do at a reasonable processor price because of the wacked database organization of PHPAudit. So, I do not recommend anyone to buy PHPAudit if it is planned to run it alongside of vBulletin. Too much hassle.
I, personally, am planning to code a sales system for vBulletin based on modded subscriptions, but at this point that's just a plan.
true i now some of the bugs on this system well i will go back to using my old system coded to vBulletin