As far as I see demand has gone, up, over the past year the requests have gone from the odd one or 2, to now it seems no matter where you go or look theres someone asking about them.
Prices and locations could be debaited for months. the OP was asking if there is enough interest, and yes there is. If he can produce the goods or not is another matter.
So in reply, there is a RISE in interest yes. If he can make them at a good price, I would guess around $50 which is half the price of a LINK97 then I'd say thats a good thing.
IDE- OK, I would prefer a internal IDE myself over a SCSI, if anyone has diagrams to build on I will consider developing a small kit. Though internal stuff not many people can do if it involves soldering. Plugin stuff like the LINK is what people want.