there are alot of small manufacturing plants around here, so the scrap yards generally have some good odds and ends. Unfortunately, when the price of scrap goes up, the amount of stuff they keep to sell privately goes down. It is one of those buy-it-when-you-can situations. There were a few scrap yards around that were known for holding brass, bronze and other stock pieces for hobbyists. When I was at a large steam engine/thresher show in Lancaster PA two years ago, there was a guy that sold such items and I had severe sticker shock.
In addition, alot of companies are getting very frugal about what gets disposed of and how. There have been a few arrests here of steamfitters and construction plumbers that "accumulated" copper. (One guy had fingered a few tons of 4 and 6 inch diameter copper pieces)
What kind of bar stock are you looking for? I may have a piece in the shop.