Just based on looks and weight this seemed like a decent find, turns out these are still sold for a bit more than that. Except for a few stains on one woofer they look new, and came with the power cord and speaker cable.
Everything's fine. My pre-purchase "tests" are
-
Tapping the cabinets with my finger to see if it sounds hollow or solid and damped. This is without checking the model first, just a general test. The solider and quieter the thump sounds the better it is. You want an acoustically "dead" enclosure.
-
State of the cones and surrounds, and tweeter. Tapping the woofer in the center gives you an idea of the bass, how smooth it moves, and any rubbing sounds. The surrounds need to be intact.
-
Tweeters, if you can see them, generally just need to be shaped right, ie no kids pushed them in. (Which isn't always bad, they can be pulled back out but why bother)
-
Do the ports have dead mice in them?
-
Smell and cosmetics. Rattles.
-
These are active speakers, so I tested to see if it turns on, if it makes a noise, is the volume pot scratchy.
The only thing I missed is that one speaker is missing its adhesive feet. Beh. Whatever.