I remember reading somewhere (I read a lot so I don't remember where) that D40 and D50 use flex boards for the sensor mounting, i.e. it is possible to unsolder it pin by pin. D70 is more difficult as it is a normal PCB.
That is one of the reasons I got D40 first and was planing to get another one. But the D70 for $12 + postage was way too cheap to miss, broken or not. As you said usually they go for around $60. My highest bid was actually $40 but nobody else went that high
I doubt that the Ukrainians + people on CN had access to proper vacuum de-solderers. I don't have one either (apart from a hand vacuum solder sucker). I may try Chipquik (the sensor may be too big for it) or copper braid
