The sale does appear to be over though. Be patient though because Cambridge has sales quite often.
Cambridge Soundworks has sales twice a year - roughly December/January and July(?). You can also buy their open box items through ebay - they are seller "hifi.com". They also have an outlet site with open-box prices. I noticed on the right side of my screen there is a 15% off coupon on 24hourdeals.com and couponmountain.com.
Why the M50? Do you have other CS speakers? The reason I ask is that I tried both the M80 ($200/pr on sale) and the M60 ($180/pr on sale) and was disappointed. The M80 was great on mids and lows but lousy on highs. The M60 was great on highs but had little depth. In fact, both the salesguy and the manager of my local store prefer the M60 over the M80.