For less common, high end stuff, I see GB making sense. However, with sales tax on things, their 1% fee they added to the buyer for collecting said tax, credit card fees, and shipping costs I am shying away from GB more myself as a buyer.
Plus, had a questionable seller sell misrepresented items (polymer Beretta take off parts he put in new Beretta steel parts packaging) and GB did NOTHING but send me a form letter. I have heard that they are very much in favor of the seller and could care less about the buyers. Now, I only know of my one case but that seems to be the way it is to me.
I'm going by my local shops more often to check inventory.
Would rather support the local guys, am tired of all the costs after the sell, and GB allowing questionable sellers with no action against them doesn't sit well with me.