I should've kept all my Batman sets in the boxes, and made a fortune of them. I can't believe they're hundreds of dollars now.
The only thing that's really special about them is the minifigs, you can buy all of the figs and maybe stickers off of Bricklink, and use what bricks you have and order some more, and build it yourself with instruction from the LEGO site. (I know I basically just restated BrickBlog, but with more detail)
You might be able to find them fairly cheap on eBay, but I sort of doubt you would find them for much less, unless they're open.