You’ve only got about three hours left to make a bid, but if you’ve got $1,450 or so you can get a new-in-box LEGO Set #118, the “Electronic Train” from 1968. From the eBay description:
is a train set that includes a locomotive, ‘coal car’ (which houses the batteries) and a couple pieces of track to display the set. But here’s why the set is so special: it is one of the first uses of electronics in Lego toys! There is an electronic ‘brick’ included in the set (see all pictures), a special whistle that gives off a certain pitch, and a microphone (white block). Once you put three 1.5V ‘C’ batteries (not included) in the ‘coal car’ the train is ready to move! One blow on the whistle and the train starts forward AUTOMATICALLY! It will continue to run until you blow the whistle again-then it will stop AUTOMATICALLY! On the third blow it will again resume going forward AUTOMATICALLY!
Two more pictures after the jump.