I got a set from Harbor Freight about 2+ years ago for under $15. I've used them for stamping other things and they seem to hold up well. Even if they only were to withstand use on 4 or 5 tubes it's still worth it to me. If there's not a Harbor Freight near you they can be had at http://www.harborfreightusa.com/usa/...o?itemid=35121
. It doesn't show a price.