Anyone who pays $15 for these things is making the rest of all of us pay more as well, I mean cmon there the same dam thing as a regular carto but a very small change of how the coil is made with one more small wire. With that said there is NO WAY I'm paying $15 for a box of 5 cartos, especially when good Boge cartos can be had for $0.80 each ordering from Eastmall or other suppliers right from China. Not for nothing but new product is happening all the time and you really gotta pay through the roof for it these days, I use to do it but no more, now I wait a good month or so until it's proven and the price comes way down and now I'm saving and also not buying things that aren't any good. These cartos are OK, I have used one of them but not worth $15 for 5, not even close in my opinion, I have to say hold and if we all do the price will drop and drop by a lot.