upper manifold

My upper intake just went. Went out to my car and turned the key and nothing. Could have swore the starter was bad. Had to have it towed and my mechanic said the plugs were filled with gas and I was low on coolant. Knowing the manifold defect with many GMs I kind of knew at that point what it was. Never expected it to strand me though. I figured it would slowly start to leak coolant and I'd have time to schedule the work. Nope. Anyway he said the upper manifold was cracked on the inside. He replaced it, the lower intake gasket, six new plugs and a LOF for $572 ( not counting towing). Also, he used the aftermarket parts which are supposed to be better than GMs.