Yeah, seem you found them before others noticed their performance.
1300-1500 is current pricing for these now.
I like the 1-slot solution as well with only a 6-pin power.
You got yourself a great deal there for the solution at hand.
And I don't think prices drop on those cards too much on the second hand market either unless you use them for far too long.
So you could off-hand them even in a Crypto market crash if electricity becomes too much for a decent price while the gaming cards would price-drop considerably.
NVIDIA quadro was never used for mining because performance was not there, this new quadro series nvidia really upped the memory bandwidth plus gamng gpus are very well sought and unrealistic at those prices, so yeah people go and look for alternatives, however the rtx a4000 still not a good deal, in the end only nvidia and manufactures will be earning money here, lucky will be the ones that buy that quadro gpu and reach roi.
The best time to sell the gpus will be in the first moment the market starts crashing again, that is the time crypto will not recover anymore, the hype and fomo is over, now is only manipulation at hand, manipulators will pump this last time and then gameover.