Converting a X to a XT

Hello, I am considering buying a cheap Subaru Forester X. It has a engine that will need replacing after a little while. Should I buy it, wait for the engine to die then put a better motor (probably from the XT) so I can upgrade it and put a turbo? The car is 2400, the body is clean, so is the interior and it's a 5 speed manual and currently runs and shifts pretty good for 250,000 I think it would