Big box stores are almost never good venues for auditioning speakers. But they're the ones that carry mass-market lines like Polk. And Polk is constantly churning its line, so speakers are regularly disappearing. The PSW 505 sub is already discontinued, for example. You may be better off choosing from among the options that are available near you.
There are specialty audio stores in both cities, and in New Jersey (which I presume you pass through regularly). Google "audio stores" and a location to find them. The only one I know personally is Audio Nexus in Summit, which certainly carries some speakers in your price range. In the specialty shops, be prepared to resist the pitch for expensive speaker wires.
If you can't explain how it works, you can't say it doesn't.—The High-End Creed