I got rid of my old computers, it would have cost as much to fix as to buy a new one.

They have CPUs for sale here for as little as $250... and more if you need a new monitor also.

Macs are good, but they operate on a totally different system, so you'll need time to learn that and get comfortable.

If it's just one heat sink, that wouldn't be so bad, but since it failed then it may have allowed the component it was protecting to heat up and fail also.