More importantly, I think, is the rep of some of the sellers here.
Many of our 'resident parts guys' have done hundreds, if not thousands, of successful transactions here. The best thing you can do for the FABO membership is to leave feedback, and perhaps a 'Kudos' thread for a good deal. This gives plenty of info for anyone who will 'take the time before dropping the dime' on used parts.
Do your homework, never impulse buy. If the guy does you right, blast it all over the forum. I do.