Those speakers are Polk's budget line. I would not pay more than $400 for those speakers personally. If you like the Polk sound, I'd recommend the Rti8 speakers. I own these and they are excellent. I would not pay more than $600 for those either though.
I can give you more suggestions, but first let me ask you what you will use them for. Are they to fit into a surround set-up or are you buying strictly for 2 channel stereo sound. Also what type of music do you listen to, how much bass are you looking for, and how loud do you like it?
Thanks for the response Kano. I am buying strictly for music, for the living room. The music I like is blues, non-heavy rock, folk, classic vocals; Sinatra, Billie Holiday, Dillon, U-2,Sting, Neil Young, etc. I like a good amount of bass but not booming or house shaking by any means.
Thanks for any suggestions. I am looking for quality and would be willing to spend a little more if I need to.