If its out of warranty id go for the open the thing up reseat the heat sinks with some good thermal paste give it a blast with a heatgun and fire her up.
The original PS3's do seem to be failing with a worrying regularity but the rest of the SKU's seem to be holding up really well.
Paying to get it fixed then flogging it is a little bit naughty IMHO. Once a machine has YLOD'd it seems to be destined to repeat the problem. You are just condeming your purchaser to the same issue.







