There are some businesses in the Charlotte / Mooresville / Concord area that sell used racing parts. They get items from usually the bigger teams like Roush, Penske etc. and these items sometimes include aluminum quick lift racing jacks, jack stands and other garage equipment. You might check some of their web sites or give them a call. I have found bargains from time to time. Prices for the racing jacks will be much higher than Sears or Sams but they are the best quality and very light weight.
Also if you live near here there are auctions at various race shops several time each year - usually in the fall and winter. I have gotten some great buys on shop equipment at these auctions.
Here are a couple of sites for used parts:
http://www.2ndchanceraceparts.com/
http://www.davejensensouth.com/
http://www.musclemotorsports.com/