Where are you getting the sub from?  
AudioAdvisor.com has the 12" new for $400, refurbished for $250, and the 10" new for $150.  The estimated shipping prices for me on the 10" were less than $20.
Since you guys are discussing subs, I have a question.  I have a small room (12x12x8.5), and I'm about to purchase an entry-level HT system (Onkyo SR602 and Athena Point5 MK-II speakers).  With this size room and that system, would the PS6000 provide too much bass, or would I be better off going with the PS4000?  Would there be any problem getting a refurbished subwoofer?  The only other sub I have looked at is the Dayton 12" at Parts express .com (do a search for dayton 12").  How does the Dayton compare to the Athenas or other subs in the $200 price range (after shipping)?  If it matters, I'll be using it for movies and music equally.
Thanks for the help.