mukwah,
My advice mirrors what the others have said.
I've bought 2 guns on gunbroker, and both purchases went great with no surprises.
I bought one new (S&W M&P 357 sig) from a dealer, and one used (FN FiveseveN) from an individual. The dealer is a very reputable one with great feedback. The individual was a new seller, so I called him and spoke with him before bidding.
Just a suggestion; if you haven't, check to see if there is an online classifieds forum in your state. Here in Virginia, we have
www.vatrader.com and I have bought several firearms listed there. The vast majority of the sales are face to face, but dealers will sometimes post listings for FFL sales as well.
Hope this helps.