Shutter speeds at high end are often off, even after CLA, though a full stop is a bit much. Was his full stop comment based on shutter speed tests done by the shop that did the CLA? Or was it an approximation? Who performed the CLA?

Shutter service alone should run about $80-100 (try Paul Ebel or Flutot's) but if you had a recent CLA then a) it wasn't done correctly, b) another servicing of the shutter won't help, or c) it's got a problem that will result in off speeds again after service.

I agree with Ian that you can get a nice 124 or 124g that doesn't need servicing for $200, but I don't think you can get one with a recent CLA (by a reputable repair person) for that price.