I was looking for engines on Craigslist and ran across this ad for a "small rocket engine test stand." Rockets are not an uncommon sight in Huntsville (see below), but this is still not a typical Craigslist find.
The seller describes the stand as "a gaseous H2/gaseous O2 rocket engine demonstrator that developed about 7 lbs of thrust." If you're concerned about the test stand not working properly, don't worry. The seller assures that "two rocket scientists have told me they saw it perform [in the early 90s]." The stand can be yours for "$1000 green cash, silver coins, laptop(s), van, and/or other trades."
Here's a slightly more detailed picture: