OOOOH those are actually really cool and pretty hard to come by these days. Cant say what a good price is because i've never actually seen one for sale and it is something i check for every now and again.
*add* alright so after a little bit of research i came across this which appears to be an official press release on the news group freenet.sci.comp.atari.product.jaguar.summary dated Mon Mar 21 15:34:57 1994 "The Cat Box will begin shipping early next quarter at an MSRP of
$49.95. ICD is taking orders now with shipments expected in May." If that was the price it was actually released at i don't really know, seems pretty low to me given how much stuff this thing does and the fact that it appears well made.