this car has to be worth all the trouble i go through

So we get my car back from another bout with the mechanics at subaru.. they say that they are pretty sure i have a cylinder misfiring and it should cost 800-1200 dollars, this is causing my car to have a rough idle, less than idea acceleration, to heat up inside very quickly due to the exhaust heating up due to gasoline collecting in the exhaust after its not being used by the misfiring cylinder head, my gas mileage is at an all time low, i got 45 miles out of a quarter tank... ... none the less with gas prices at 2.85 ... but i dont know if this car is worht me fixing and im thinking i might wanna sell it to a member of the forums, but i am gonna get a second opinion its so rough to decide.. damn 92's with 87k