Join the PGCA, some nice guns sell here but only PGCA members have access to that part of the web site.
I find auctions are a good source too.
What part of the country are you in? There are a couple of good auctions here in New England that get some nice guns. In fact, next weekend there are a couple Parker's on the auction block at Amoskeag Auction in Manchester New Hampshire (
http://www.amoskeagauction.com/ ) .