I see comparable prices on eBay for 1/700 kits from the other Japanese makers, $60 or so for an Akagi from Aoshima, for example.
I was just stunned now to see an eBay "Buy it now" offering of the Revell 1/720 USS Intrepid, in its present Revell of Germany boxing, for $33. That is way too much for that kit. Not saying I wouldn't build that kit, but I wouldn't pay more than $10 for it.