... and have also had several Leica R3 models (a close relative of your Minolta) serviced
The Minolta XE-7 was a close relative of the R3. The Minolta XD's were similar to the R4. But the Minolta X-700 is an entirely different camera from the R3 and the ability to repair one shouldn't imply that the other is also repairable.
When these older cameras were made, they sold for $200-300 with a lens.
At that time it would cost between $60-100 to repair one. Today the cameras are selling for 1/2 that and less & the prices on repairs haven't gone down.
There's no reason an Xcamera couldn't be repaired except for two things. Finding someone familiar enough with it and with some used or new parts available and cost.
All of them were designed to be repaired, some more modular than others & easier to swap parts on.