That seems like a really good price tag...
I've got a couple of these. http://www.mcmelectronics.com/product/28-0280
That I plug my "basement servers" into. They've worked pretty good. (so far - knock on wood)
You can hear the relay's kick in when you've a power drop. (Like when the wife turns on the dryer, or the central air kicks in)
I've never looked into them far enough to know if they're isolating though... Is yours?