That's a pretty tight budget for a trainer. Your best bet at that price is Craig's List. I don't think you'll have any luck with eBay because of the shipping costs.
Check out this link
http://cgi.ebay.com/NEW-RAD-CYCLE-BIKE-TRAINER-INDOOR-BICYCLE-EXERCISE_W0QQitemZ230409232028QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item35a575de9c
There were several of these up for auction on eBay. Shipping was included, and the price seemed low, but still above your budget.
If you do find something, you may want to consider a smooth rear tire to minimize noise.
Check out this link
http://cgi.ebay.com/NEW-RAD-CYCLE-BIKE-TRAINER-INDOOR-BICYCLE-EXERCISE_W0QQitemZ230409232028QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item35a575de9c
There were several of these up for auction on eBay. Shipping was included, and the price seemed low, but still above your budget.
If you do find something, you may want to consider a smooth rear tire to minimize noise.