My precious has arrived:
Normally I don't do 'new-in-box' stuff as I'm interested in the hardware, not the fluff. But here I make an exception - I'm hoarding as many Trackball Explorers as I can find, as I intend to keep using these things until either I die or there is no more electricity to run computers on, retro or otherwise. Second hand ones are a mixed bag (note the yellowing and traces of heavy use on the one not in the box), but new is the holy grail. I know I could flog this on an auction site for significantly more than I paid, but no way am I parting with this now or in any forseeable future. It goes deep in a dark cupboard until needed.
The seller had a similar attitude (indeed, that's where he dug it up from), but despite the fantastic ergonomics of the Explorer, he's got a bad case of RSI made worse by these things, and his doctor ordered him to stop using them. Sounds like a nightmare-scenario, but at least he was happy it went to someone similarly obsessed with these things 😀