Replacing a shutter - Mamiya 645AF

I have gotten quotes on replacing the shutter on my 645AF. So far, they are way out of my price range. I am in a catch 22 here because I have had to cancel a few paying jobs since my return from NM for lack of a functional and reliable camera.

So, here is my question. If I could get ahold of the parts, is this something I might could do myself? Or, is it better to try and scrape up the money and pay someone else.

Depends.
In addition to installing the shutter, it will need to be adjusted.
As the camera is disassembled you're also going to mess with the AF sensor & a crapload of other electronics that are in the way.

IMO Have it repaired or buy a replacement body. If you buy a replacement body, have the other repaired when you can afford it.