$1200 for a pickup truck that runs, drives and stops is a good deal in general. I'd be a little suspicious of a couple of owner claims though. The AC has nothing to do with the battery, other than it needs 12V power to work. More likely problem is a bad electrical connection, switch or the AC clutch itself. The "leaking heater hose" (easy fix) could actually be a leaking heater core (not an easy fix). I'm always suspicious of when a seller claims a problem is an "easy fix". If it were really an easy fix, the seller would have fixed it! The mystery ticking, who knows? For the price this truck likely has lots of miles and old trucks with lots of miles for $1200 are going to make weird noises.