We are probably going to end up signing another Garcia or two and hoping for better results. Younger free agent SPs will be out of our price range, so either have to trade for them or get some vet SPs in free agency for cheap.
If Happ is willing to come back, then I don't see why we couldn't go 2/30 on him and still rebuild. Someone's going to have to throw innings for this team next year. Obviously if better scenarios become available then go with those, but in isolation, I don't think bringing Happ back hurts at all. It's better than trying to decide which pitcher won't suck between Garcia, Cashner, Cobb, etc, and spending similar money.