Well, speaking as a camera repair technician, I can shed some light on this. For instance, you can purchase a camera with a stellar reputation for under $80. However, it’s often the case that these cameras have been stored in a cupboard for 45 years or more (in fact, I’d estimate that at least 80% of cameras on eBay are in this condition). Consequently, the chances of them working properly straight out of the cupboard are quite low. Buyers should be aware of this and expect to spend some money on servicing the camera if they intend to use it.
And so, many of these newly purchased cameras end up on my workbench for service and/or repair. Typically, a complete disassembly, cleaning, lubrication and calibration of the camera requires 8-10 hours of labor to complete. My per-camera materials costs are fairly low, but if parts are required, they can be expensive, simply because NOS (new old stock) parts are now very hard to come by. The single most common part I have to replace is a plated brass transfer rack, and my supply of these is now down to less than twenty, and they were expensive for me to acquire, so it is expensive for the client if I have to install a new one.
Taking all of that into consideration, it should come as no surprise to anyone that it costs a client between $250 to $450 USD to service their camera (I’ve been told by two of my repair technician friends that my prices should be much higher than they are, considering the work involved, but I prefer to keep the price where it is). I can assure you that what I make doing this work is not a living wage!
So yeah, the cost of servicing a camera that you may have picked up at a thrift shop for a mere $25 will likely cost you a few hundred dollars to restore to full functionality. Now you know why!