I never really thought about it before, but did you look on EBay? They have everything else on earth there. Fortunately for me there are a couple places around home that buy and sell workout equipment.
EVEN COMMERCIAL GRADE USED SMITHS WILL BE TOO PRICEY. i would go to newyorkbarbells.com and click on the smith machine link. i believe that the one that runs on rollers is about 400.00 and the linear bearing (the one i would recommend) is about 700.00. do not be fooled by the price , they are pretty decent machines. btw hippie i see that a while ago you pm'ed me and some how i missed it. if you want pm me again...sorry about that.