The high $99 eBay price seems to be because Walthers is out of stock of the
N scale IceHouse Kit, and someone is offering it for sale at that price in hopes
that someone would want it enough to pay the higher price.
When it was available, the regular price is $27.99 or so.
If it were me, I would wait and continue to look around. Somewhere, on some
hobby shop shelf, or in someone's N scale collection, is an
unbuilt Walthers IceHouse kit that they'd be willing to sell at
a lower price.
Eventually, Walthers may decide to re-run the kit.
Just my 2 cents worth.