IMB Model M 1984 Mechanical Keyboard- Untested$30 OBO + $26.18 US shipping
It's quite dirty (see other photos in the listing—you'll want some Goo Gone and a nylon scraper, among other things), and some key caps are missing. But it includes the original black AT cable, and you won't find a lower price for a 1st-gen Model M anywhere on eBay.
(BTW, when sellers ask more than $18 to ship a keyboard you're interested in, you can contact them and ask if they'd be willing to send it in one of USPS's flat-rate Priority Mail "Board Game" boxes. They (the boxes, that is, not the sellers) can be shipped anywhere in the US for under $18, and the boxes themselves are free. Most sellers just don't know about it, are glad to do it and refund you the difference.)