It is very tricky to purchase a turntable on EBay.

Here is few tips of what you should be looking:

-Anti-vibration belt driven plate
-Vertical and lateral weight adjustment
-Magnetic cartridge
-Perfect stylus (a 30x view of a well pointed needle)
-Dust cover
-Ground wire
-The unit must turn at 33 1/3 rpm (if not it could be a motor or extended belt problem)

This should give you the maximum quality to read vinyl records properly.

Good Luck !