What's your time table? If you need it now your limited to new or whatever you can come across. If you don't need it right now I would suggest craigslist, estate sales, and auctions. I personally love auctions. Check out
http://www.auctionzip.com/ and look in your area for upcoming sales. I have bought alot at auctions. I am very cheap when it comes to auctions. If I can't get it inexpensively I always know there will be another some time in the future. I have several metal workbenches, cabinets, and of course tools purchased from auctions.
If you go the auction route the only problem is you may not get exactly what you want. In your case, I suppose you want several matching and uniform cabinets for your garage. If you have a table saw you could make your own cabinets inexpensively out of mdf in the exact configuration you want. If that is not an ideal option just be patient and check every resource available in your area dilgently. Deals are out there. Talk to friends and family and you may even score some 50's vintage kitchen cabinets (metal) in a decent color for free or cheap. Too bad you missed out on the great gladiator cabinet deal. I got 5. Two for the basement and three for the garage. Maybe there will be another good retail deal in the future. Patience is the key but that doesn't help if you want it now.