I've got one of these coming, not the tank version. I think it will be fun to play around with different wire sizes, number of coils and so on. I did get a used iAtty since the new one is going to be $250! There is a cheap rebuildable out there, but it gets horrible reviews.
I'll do a mini review of them after I play with them a bit.
Save yourself a lot of headaches and just get something you can identify,and write that one off as education expense.You should be able to clean and refill the cartridges though and get some use from it.