Craigslist is the WalMart of advertising. RacingJunk is ok, but it seems like everyone is on Facebook. Lots of for sale pages there for any kind of item. The "DRAG RACE parts and cars for sale or trade in northeast" page has everything from clapped out $500 Mustangs to $150k Pro mods on it for sale.

If the results don't match the theory, change the theory.