Best UPS under $500

Looking for an UPS that will give me 20 to 25 min at full power for under $500. I have a 20 inch iMac intel core duo Tiger, 250 gig hd, that I would hate to encounter a power outage in the middle of an Apple security or other software/firmware update download.
Is $500 unrealistic for that amount of battery time?

thanks in advance!!

http://www.apc.com/products/family/index.cfm?id=23#anchor1

I believe that is what you are looking for. Also its significantly cheaper than your budget so you can also buy an external hard drive to back up your data as well.

Agree with PBG4 - APC, not the cheapest, but arguably the best. See also here: http://search.superwarehouse.com/?query=UPS

Thanks for suggestions

THANKS!
Looks like the BR900 will do fine, and by trading up my current broken UPS,
they'll sell it for $124. btw, I already have an ext. HD, a Lacie Pro 2 disk RAID. Works great!



Go Dodgers!