Most will protect your system from lightning and power surges. Amps do not always benefit in sound but it is an easy way to power up several components. Monster makes a good one in your range.
Do power conditioners really help?
I am a thinking about a purchasing a power conditioner for my system but really don't know much about power conditioners. I have a Denon AVR 5800 home THX with B&W Nautilus speaker set up. I'm also thinking about purchasing a power cable. I am currently using the Denon factory cable. If I buy a good power cable do I need a power conditioner? I'm clueless and wondering if I will hear any sound improvements. Prices I've looked at range from $30 to $2000. If I purchase, used or new, I only am willing to spend $300-$500. Comments welcome.