Keep in mind AirAsia flies DPS-BKK direct as well now. Sure it's no TG, but I'd prefer the pain of a couple of extra hours on AirAsia flying direct over the pain of a terminal transfer at CGK and rechecking in again.

Otherwise if you're still keen to go via CGK, it's worth looking at Garuda, they've often got reasonable fares (not as cheap as AirAsia, but still not going to break the bank) and all their flights go through Terminal 2 at CGK which saves a fair bit of hassle.