T205s Drum Backs
 

I've began to collect T205s and have been doing research on the different backs. I know the Drum backs are extremely rare. Almost so rare, there is very little price data on them. I've read through old posts on here regarding the checklists, etc.

However, what does a GOOD Drum common go for? I only ask because I want to feel confident about pulling the trigger if I ever see one someday. Appreciate any insight on the Drums.

Jeff