We don't have a fixed number to quote you here without seeing the door, and we're not going to make one up. What we can tell you is that maintenance visits cost less than repair visits, and repair visits cost less than replacement, in that order, every time. A torsion spring system - more typical of the 1980s-era builds common in Great Falls - runs on a predictable service interval based on cycle count, so a maintenance visit here is often about catching wear before it becomes a failure, not fixing something that already broke.
One honest limitation: if a part on your door is discontinued or the opener is old enough that the manufacturer no longer stocks boards for it, we may tell you replacement is the better spend rather than keep chasing repairs on a system that's aging out. We'd rather say that up front than bill you for patchwork.