Buy $500 unstartable 2000 S40 w/bad coolant temp sensor?

[Clevolvo]

The story is as follows: "It over heated because i left it running without driving it and it ruined the coolant temperature sensor and the thermostat.....it needs A new relay for the ignition cooling fan"
-now, my mechanic friend with Volvo experience said, "don't waste your time, that motor is already fried!- those sensors burn up for a reason, there was no coolant circulating, that's why the sensor went bad." Now, Is there no chance it's just a thermostat, relay and coolant temp sensor fix? And I should walk away from a cheap s40 with 200k on it? Or is there any hope? The fan does stay on when key is in the ignition, but it won't start. All advice and or experiences welcome.

[precopster]

It won't start more than likely because the cylinders have little compression and are full of rust. Unless you're quite experienced in removing and replacing head gaskets I wouldn't walk; I would run.