Ever since the Wm's brass articulating engines came out, I wanted one, but if you didn't pre order one at the time, after they came out the dealers were pricing them as much as $1800. each. A little to rich for me at the time.
Since Lionel, K-Line, Weaver and MTH started producing them, the Wm's have drop substantially in resale value. In the past 4 yrs I've bought all w/boxes, Big Boy, Challenger, Cab forward and NY Central class A and N&W class A, for each less then $500.
All are beautiful engines, I don't run any of them, they're just wall hangers.