I am fortunate from the looks of it. I take my old singer and my Elna to my LQS who has a repair/service man come in every two weeks and it's only $36 for a cleaning and adjustment.
Now if you need new belts or parts he won't do that until he talks to you on the phone because the parts needed are extra, but he sure does a great job of cleaning, adjustments if needed, and getting the machines ready for the next quilt.
I bought the Clotilde vaccum attachments to suck that lint out of the inside of my machine when I bought the Singer four years ago. I figured I was doing a good job of keeping it clean. When he opened that machine and looked at the belts, etc.............the lint filled a walmart bag. No wonder it went 'klunk' and froze! I will get mine machines cleaned at least twice a year from now on, I know fabrics and threads (even the best of them) have so much lint that it will eat up a machine's life!
Hugs,
Sharon