SUB-WOOFER RECOMMENDS

I'm building a Home Theatre system. So far, I have B&W CM1's for my L+R+C channels and want to upgrade my SUB.

Seems logical that I stay in the B&W world and even more logical to stay in the CM series so I guess the:

ASW10CM S2

is the logical choice?

With a list price of $1500+ I am very curious to look into what last years predecessor was and it's current price point.

Am I allright to venture into the ASW610 or 608's or keep it in the CM family?

Thanks for the advice again, any recommends would be appreciated.