Im banking on this one...

1490 Lego Bank

Description: Released in 1988 and retail price was about 20 dollars. Containing 174 parts and 3 minifigs, can be found MISB today for anywhere between 400 and 1000 dollars, this is one of the rarest lego sets ever made.

My take: What makes this set so rare? I honestly have no idea, I guess it was one of those forgotten sets that just did not sell very well or was limited in quantity. Playability looks pretty limited, you can probably stage a bank robbery or something, but why would you even want to touch this set? If I had it I would seal it air tight and tuck it away! Until next week!