I've got some gigs booked with this guy over the next few months and if we gel then I'll probably play with him more. He's looking into getting the Shure PSM400 wireless monitor system and so if I want to use it I'd need to buy my own receiver. That's quite an expense for me at this time but if we do gel and I start playing more gigs with him then I'll probably end up getting the receiver. I'm just wondering something. Shure sells their E3 earphones with that system but I'm wondering if I bought, say, some Etymotic ER-6's for much cheaper would those come even close to working as well? I previously used a wireless monitor system with the old band I was in but I didn't have to buy my own and I had the professional earphones that were matched to the system. I'd also appreciate any other suggestions you might have for a quality but cheaper solution to the E3s.