Out of all the mods listed here so far I'd recommend the Evic VTC as the best value buy (the "last a good while" qualification pretty much eliminates anything IPV imo). Had trouble with my first one i had to warranty (which seemed to be a pretty rare thing among people posting here and ECF), but my second is going 8+ months strong with some quality wear and tear mileage on it.
www.eciggity.com/joyetech-evic-vtc-mini-body-only/
Cheapest price i see. Reddit10 coupon puts it at $39 shipped.
Although fair warning, Joytech's warranty policies if you need it can be a tad frustrating. Expect them to jump you through extensive hoops before they'll be taking any kind of loss on a defective product. Think i ended up sending the same 2 videos to 4 different reps, who would then refer me down the line to another, before finally getting one weeks latter that would ok an exchange. But that is pretty standard business practice on the chinese front of ecig products. Cheap prices backed by cheap CS.