Ayu's in-ear monitors (that's what they are) probably cost well over a $1000 since they're custom made and it is professional equipment, so I don't think you'd buy em just to use as earphones for your Ipod or other portable players, I don't think you'd hear much of a difference than with a good pair of earphones, when using em just for that.
In-ear monitors from Shure start at around $600, these come with a wireless system.
there are cheaper ones of course and without receiver and stuff, but if you're not up on stage or anything, I'd rather pick up some really good earphones (not too expensive)....or some Ayu stuff..or maybe a plain-ticket to Japan..but that's just me
but if you've got like lots of cash, go ahead, why not? Ayu's look awesome, I don't think I've ever seen em like that, on any performer..
