Ray's not here at the moment, so I'll say it.

Sell the wife.

It depends upon your listening habits (loudness as well as content). If you've never had a sub before AND you watch movies a lot, it might just be better. OTOH, if your primary use is music and/or you listen at high volumes, I would be concerned that the "difference" might not be something you'll enjoy.

bibere usque ad hilaritatem