Not sure where you are checking your prices at?
Here are just a few from the last couple weeks.

One lens that sold for $269:
http://www.ebay.com/itm/Mamiya-RB-RB...item4d0672470f

Another sold for $140:
http://www.ebay.com/itm/Mamiya-RB67-...p2047675.l2557

One that didn't sell for $249:
http://www.ebay.com/itm/Mamiya-RB67-...p2047675.l2557
I will put it up on Ebay now for one penny listing before I attempt to sell this lens here any longer.
You may not feel like dropping your price...
but I would advise dropping the attitude.

Good bye!