Gunsamerica used to be a great site, but they changed their format about ten years ago. That infuriated enough people that it led to Gunsinternational being formed using Gunsamerican's old format. Eventually GA got the message and reverted to the old format, but it was then too late. I recently cancelled my dealer account on GunsAmerica because they set up this system where buyers can inquire of multiple dealers in a "shotgun" approach to solicit a price quote on a particular gun. Can you image the irritation of an inquiry from some Bubba wanting your absolute lowest price on a Savage 110, only to find out he solicited a price quote from fifty other dealers? GunsAmerica keeps shooting themselves in the foot and then reloading.
For auctions I use Gunbroker because they make it easy to set up the auctions and the auction format forces the buyer to follow through with payment. High end and specialty items sell better on GunsInternational because normally there is a lot of back-and-forth personal contact required when selling a high end piece. That negotiation is better accomplished over the phone rather than via email and the GunsInternational format facilitates that process. GunsInternational also has a provision to pay for the listing up front and deal directly with the buyer on price.