I'm really trying to understand how Amazom are selling the SB-900 at $424 and the older SB-800 at $600 ??? Recently, I bid on a used MB-D10 motor drive on ebay because it was cheap at the time, but stopped bidding when the price came too close to the price of a brand new one. The final price had surpassed the price of a new one (which I eventually bought) , but I couldn't help thinking , are people that stupid that they'll pay for a second hand one , plus postage, more than the cost a new one ? It beggers belief !