I have a Mamiya C330 body that has significant frame spacing issues. It is very solid otherwise with the usual cosmetic signs of use. Key Camera in Longmont, CO gave me a ballpark cost of $125 to $150 plus parts. Note that this was based solely on my description of the frame spacing problem - Key did not see the camera.
Bellows are light-tight, focus and shutter cocking mechanisms work well. The waist level finder has seen better days but is functional though the magnifier flops a bit when retracted. $150.00 OBO plus shipping to North America, no fees to me.