A 6ft piece of 3/8" round from McMaster.com is about twice the price I pay for quatities of 500ft from Reliance Steel (this is in the Los Angeles area) For small quantities that's not too bad. Shipping will get you though.
I'm looking for small pieces around the 3' length. I just bought some from SPEEDYMETAL on Ebay tonight...but looking for more. Thanks for the help so far!