Normally, I don't fret too much about where I buy stainless fasteners. Sure, the prices vary, but when you need something, time and convenience seem to offset the typical few cents difference in fastener prices. But, when I couldn't find stainless 12-24 set screws, I had to go to a local supplier. In Tacoma, we have Tacoma Screw. What a difference: A similar size set screw was $.06 each (vs .49 at Ace Hardware), 3/16" pop-rivets were $.24 ea, a 5-roll pack of electrical tape in assorted colors was $5.00, a pre-made 1 GA batter cable was $15.00. They also had a huge assortment of paints, primers, o-rings, and plumbing supplies.
Sometimes it pays to shop around....
Sometimes it pays to shop around....