the dealers have a different contract with ebay, i was in charge of all of our ebay cars for 2 years and I saw this happen. Granted, the car was marked for 2k rather than 20k. so we never sold it... how far off from blue book did you bid? Take a civil approach first, and when it doesnt work, if you really want the car, get nasty.
01 E46 LSB 6 Speed (Gone), 05 545I (Gone), 08 550I (Gone), 11 E92 M3 Int blue DCT- Megan Exhaust, Drop in BME Air Filter, CF wing and splitters.