Right hands ... wrong hands. Who is to judge? No-one is forcing anyone to buy that stuff.
Screwball? Don't you mean "the highest bidder" (just as long as s/he can stump up the funds)? And why "screwball", anyway? Maybe the buyer is a vet, or a tech looking for spares to fix charity kit ... there are many possibilities.

Equipment (both new and used - plus parts, manuals, and all the rest) gets bought and sold the whole time. That's how the commercial world works. Medical equipment on eBay has often been bought at one of the auction houses. With Hilditch being the most prominent. Some others have been known to offer
ex-MOD test equipment.
But when you
sell equipment to Hilditch
et al ... what do you think happens to it after that? Hint:- it gets sold on, to the highest bidder, at auction. The buyers are often dealers, so the items are usually sold on again (and possibly, again). The eBay crowd are generally small time operators, in the main. It is doubtful that any of them add value to the equipment being sold (by having it serviced, for example, or finding a manual to accompany it).
Meanwhile,
donating equipment (to charities sending good used equipment overseas, for example - and I urge you to do just that!) is a completely different ball-game. But one that has nothing to do with chancers trying to make a killing on eBay. In short, folk involved with the charities tend not to be motivated primarily by money.
Anyway, wherever that gear stuff has come from ... it almost certainly
won't have been Afghanistan. Unlike (it seems) the NHS, HM Forces have systems (not to mention mind-sets) in place that track and maintain all assets.
So, may I suggest that the real questions you need to ask are along the lines of:-
1) Why have your pumps gone missing?
2) Have they been stolen (how come, and who are the suspects)?
3) When are proper property management procedures going to be put in place?
... and stuff like that.
