theres one of these used at a guitar center here that is about $500 (i'm sure i can talk them down to make it 500 with sales tax included). its the 24 channel version which is probably more than i'll ever need but i'll deal with it. has anybody had luck with these? the search didn't come up with much. really i just want to know if its worth $500 or if i'd have better luck with something newer with less channels since i really only need 12 at the most.