I had a Gammill Classic Plus that I added the Statler Stitcher to last fall. I have a ton of money in it and I don't regret spending a cent of it and would spend it again without a second thought.
Maintenance expense is almost nothing. Keep it clean and oiled and it will run for years. The manual and other documentation are excellent and I just finished an all day class where we adjusted tensions, checked and corrected (if required) timing and all other mechanical aspects of the machine. Other than electrical, I can't see every having to have service on the machine.
You dealer and support network is the most important part of any system.
You can't take it with you so you should have what you want while you can enjoy it.