Make a lowball offer to the seller. A basic clean/lube/adjust will run close to $200, and you obviously will need some parts. Do some research to find out how much a lens/shutter overhaul will cost, and subtract that from the price too. Same for the film magazine if it has one.

Unless the camera shows signs of a lot of wear, you probably can talk your way into a decent bargain. Once it's all spiffed up and tuned, it will last you for years.