When I visited the Computer History Museum three weeks ago, I also stopped at two electronic surplus shops, WeirdStuff and HSC (I also visited these stores back in October). Unfortunately, the pickings were slim.
At WeirdStuff, there was a Tektronix 502 oscilloscope. Unfortunately, it was priced at $160.
The Tektronix 7904 that I saw last time was still on the back wall, now with a sticker that says "no power", but still with a price tag of $250. (This scope has been there for at least six months.)
I think both of these scopes are priced five times too high. Fifty dollars is a fair price for a broken 7904.
I saw similar overpricing at HSC. They seem to have a lot of untested gear in the $45 to $75 range. I buy a lot of electronic surplus junk, but my what-the-hell price (as in, "what the hell, I'll just buy it and see") for a random untested, unidentified box is a lot less than $45.
However, I have bought things at HSC in the past, and I will buy things at HSC in the future. For one thing, I appreciate and support any business that does this:
This picture shows part of the databook library at HSC. This collection of databooks puts the collection of databooks in the M.I.T. Library to shame. I have referenced these books in the past, and I hope to be able to reference them in the future. Not everything is available on the web (as my commentary in the "Bibliography of Jim Williams" attests). Having real, printed databooks and handbooks available for perusal is a valuable resource and a public service. Thank you, HSC.