That is way too much to pay - yet another ripoff rebrander selling a model that is not compatible with much.
I am glad you found your way here. If you like the style of the Duo then instead look at Vapor4Life.com and SmokelessImage Volt. Those are 2 styles of KR808D-1, the more compatible and well supported model. I highly recommend manual
batteries so you can refill the cartomizers without worrying much about the occasional leak damaging or killing your battery. Most people here use and recommend manuals. The Vapor4life has a nice-sized button and mostly sealed
threaded end. The Volt has a rubberized finish, slightly longer charge, a totally sealed metal end but a very tiny button and a shorter safety cutoff of about 5 seconds (if your drag is longer it will flash and after the flash you can drag again, vs the Vapor4Life where you can just drag longer). I use both. They can use cartomizers (prefilled and blank) from vapor4Life, Smokeless Image, Halocigs G6, Bloogplanet Maxxfusion.