I have picked up a few odds and ends from 'The Bullet Lady' on Auction Arms, and have been very satisfied with her procedures.

I got my Pedersoli Sharps through GunBroker.

I watched the site for three months, and missed out on the only .45-90 (a Quigley, I think) that appeared...so I settled for a .45-70.
Because I'm honest, and so was the seller, the experience (for both of us) was positive.

Having mastered the art of sniping (on eBay) I found their 15 minute rule disconcerting, and I ended up paying a bit more than I had hoped to.
I wanted the gun, and the end result had me owning it.  So, the two 'time extensions' didn't change the final outcome...but the seller got a better deal.
I wish those guys with their puny (and seemingly endless) five and ten dollar raises had just stayed home.

Still, $800 for a Billy Dixon in perfect condition - with a USA 431 tang sight - was a pretty good deal.

The seller was a gunshop in Missouri, so I had them send it to Lee Shaver (also in Missouri).  He checked the piece more thoroughly than I am capable of and reported that it was good...so I decided not to have it sent back.  Lee rechambered it to .45-90 and sent it on to me.

I have never tried selling anything through those sites, but my purchasing experiences have been good.
CM

Never buy a gun without a picture-i did once and even through i returned it they charged me a 20% restocking fee-which i regarded as theft.It was a so-called "Webley RIC", it was a cheaper than dirt "British Bulldog", either the seller didn't know what he was selling or he didn't care, i don't know. Don't except to see your rifle next week ,either, i bought a rifle on Gunbroker Aug 11, and it's not here yet. Seller claimed he put the wrong label on it, sent it to someone who bought a flashlight, instead? He can't tell the difference between a package containing a flashlight and a Winchester Low Wall? I e-mailed him about this and now he's angry cause i'm not sure here's 100% legit-i'm not sure.

On GunBroker, you are dealing with the individual seller and not GunBroker.  DO NOT rely on their supposed fraud insurance ($400 max), which is close to being as fraudulent as some of their shadier dealers.  It took me a full year to get them to pay up for a case where the seller sent me something different than listed (and pictured).  Thanks to The Shotgun News’ policy of leaning on malefactor advertisers they finally paid up.  However I’m still out 100s of dollars and lots of time…..and for someone relying of mail fraud charges for protection, I’m still waiting for the Post Office to start an investigation on the complaint filed 13 months ago.  They just don’t have the time or inclination to go after small time fraud when there are so many out there.

Once burned, I’m much more careful who I buy from…..and pass on listings from folks that I can’t get some real intel on.  Life is too short to spend a year chasing a bum seller and GunBroker.  Remember that even a good picture means nothing if you don’t receive the firearm pictured.

I also second what Dave said. In addition I wont buy from anyone who doesn't have some positive feedback! As for Jackthedog, he's a close friend, and I rarely sell anything that I don't let him handle the transaction for me! I knew him before I used his service, but I send all my local acquaintances to him also.