As long as there isn't physical damage to the camera, restoration of a Contax IIa/IIIa isn't difficult. It's the amount of time to do the work, and as always, time is money.
The Contax IIa is very simple to disassemble and to reassemble.
However, the capitalist marketplace bears what people are willing to pay. So if the cost or wait isn't to your liking, you simply take your dollars elsewhere.
I believe there are some others who repair the Contax. I thought Essex did this work and Midwest Camera, but that was some time ago.