too bad you don't live closer I would lend you a set.
as BBM points out you hub type spacing may drive price. if you need a 8spd+ cassette to match your bike they will be more. older freewheel types are pretty easy to come by.
__________________
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk