35S Insanity

[everettr]

So I am browsing through the Auction place. looking at calculator offerings, as one does. I look at a Swiss Micros DM42 listing, the price is okay. and then I look an anything else the seller has on offer. HP 35s for $300? Is this a listing typo?
I just did a search in the E place and $250 is the minimum asking price and NOS is over $400!! Why?!
I have an HP 35S that is barely used and that I really don't think about very much. Most of the thoughts I have had about it involved some way to kluge an input port/external storage by hot wiring the keyboard matrix. Thankfully, my 35S remains as HP intended it, so I can offer it up to the ins... discerning buyers that obviously know something that I do not.