I try to wait for OHC of current books if possible. If not Ill by Premiere HC. Ill by Classic TPB and Ultimate Collections as they are priced well. I wont mix formats so once I start i dont switch from HC to TPB or vice versa. For Classic books i buy Masterworks and upgrade to Omni's when they come out. I dont buy any Essentials or Showcases anymore, i dont like black and white.