The other option is ebay or your local computer recycler for a new or used one. I bought a brand new Powerware 5115 1400 va from a auction that wasn't worded well. The guy just listed it and didn't give the sub model so it could have been any of about 5 big to small ones. I asked him which one and it turned out to be the biggest one they make in that line. His starting bid was 139 and that's what I got it for
156 to my door double boxed brand new. He had to honer the bid as he didn't set a reserve just the opening bid price. He never tried to get out of it, I thanked him for a smokin deal and we both got positive feedback.
Another e-bayer tried to get the same deal but he had changed his auctions so it had a reserve and like that with a better description and the guy managed to leave so much negative feedback somehow he lost his user name and disapeared, He had like 1500 almost all positive before that.
I also found a computer recycler guy that was selling used APC 1400's of varying types for as low as 40 bucks, less if they were broke. We bought several and made 3 or 4 good ones out of the extras. I did get a good one for myself so now I have two big UPS's for both machines here.
Both of these will run a full tower with everything and a 21 inch monitor for around a half an hour with good batteries.
The Costco one is a deal if you just want to walk in and walk out with one
