$1500 is a smoking deal.
I would strongly suggest a piston soak before you went that route though. If it's just the one valve and it's the intake I put money on it that it just has carbon build up. Marvel Mystery Oil down the spark plug holes let sit for "some time" at least 1 hour 24 hours is better. Leave the plugs out, pull the fuel relay, turn it over to get the excess out (last step is voluntary not necessary). Seafoam spray intake cleaner will do the same thing with the carbon, you spray down into the intake after the MAF sensor. MMO works better I have found. Takes longer but works better and also has lubricating properties the seamfoam doesn't.
Be aware you will smoke out your entire neighborhood as all the carbon build up burns off.
A leaking intake could in theory make the engine run very lean. Which "could" attribute to some overheating. I wouldn't say a constant 30 degrees though. If you have someone with software (Hp tuners or similar) that could monitor knock plus how much number 2 is retarding to prevent the knock you can see how bad that cylinder really is.
Again smoking deal for head replacement but I would hold off until you just tried to free up that valve other methods. If your coolant isn't disappearing I am pretty confident that your head is still good.
