If you are seriously considering adding a Devil to your collection, You've got to be prepared to pay a serious price.
You need to budget $250 for one.
Some times you can find them for less BUT with all of the people interested in tamagotchi again, you are really going to have to luck out big time to get one for around $100.
Be patient, the devil tamagotchi isn't that rare. I've seen quit some passing this last year on Ebay. But I'm still sad because I forgot to place a bid on the black one *criessomemore*. The prices ranged from 100-150 usd dollars last year.