What's a reasonable price? How big is your space? What are you expectations in terms of output? Just a little fill, or are you wanting to pressurize your room?
It looks like those came out almost 20 years ago. I wouldn't pay much for them or expect much output from their 8 inch drivers. If you have a small space and want subs that will add a little heft to the bass and not take up much space, they might be just the ticket.