Go to Ebay.
Just to the right of the blue "Search" button click "advanced"
in the first box enter what you are searching for (i.e. "proto board")
(keep it simple)
scroll down a bit, click "sold items"
scroll down a bit more, click "US only"
scroll all the way down, click "most recent" (or however you want the listings sorted)
click "search" at the bottom.
Not really a lot to it, and I don't believe you need to be registered on Ebay to use that function.
The comment above about ridiculous asking prices is dead on. I've been watching a set of Indestro boards that have been listed for
months at $149 for the entire lot, with no takers. (Might be because it's "local pickup only" somewhere in Iowa.)
http://www.ebay.com/itm/17-wall-mou...827959?hash=item51f3836e77:g:dFAAAOSweW5VThHQ
Shipping will be a killer. As I recall, the boxes we got those boards in were about 25" x 25" x 8" - one board to a box - all had double-corrugated inserts inside to prevent the boards from being damaged in transit.