blown head gasket and stuck valves in 2015 Toro Zero turn? Fix or buy new?

I just found out that I have a head gasket on one cylinder and stuck valves, with bent push rods on the other cylinder. The shop thinks by overheating, but it had plenty of oil, but the ethanol crap gas was old. They think that might have destroyed the engine. Does that sound right? I gather it is pretty easy to replace the gasket, but I'm not sure about he other cylinder problems, and the shop has not spent the time to look into it in detail. They recommend replacing the engine, or buying a...

blown head gasket and stuck valves in 2015 Toro Zero turn? Fix or buy new?