Look at trailerpartsdepot.com. I bought a whole set of urethane rollers for a small trailer, and they were "blems", and were super cheap, just over a dollar each. In their parts list click on "Clearance Items" to see what they have. Mine had "color variances", but they looked and work very nice. Those guys have anything you need, and it's wholesale.
I'm an Eighth Day Adventist. On the Eighth Day, God went fishing!