$600 is a pretty good deal. Most shops charge more.
There was a class action lawsuit that might've paid you some money, but you were required to file for payment back in October. I think you're S.O.L.
Personally, I always recommend that people take care of this intake gasket issue BEFORE it becomes a problem. You may have got lucky, and caught the problem before the coolant in the oil did any damage. But lots of people go at least a week (some much longer) between checking oil and coolant. Running an engine for a week with coolant in the oil will ruin it.
My brother bought a '97 Olds Cutlass Supreme a year or two back- had 30,000 miles on it. Little-old-lady-car. I convinced him to go ahead and update the LIM gaskets to the new Felpro design. When he took it apart, he could see that the original LIM gaskets were already split and starting to leak... even though there had been no VISIBLE sign of coolant in the oil.