>The GTX 1050 Ti is still a current, sold product, selling for $250 or so USD
That's very misleading. The card was released more than 4 years ago and has a MSRP of $139[1]. It's neither a current or expensive product.
The $250 price is almost certainty because it's "rare", not because it's actually worth that much. See for instance, i7-6700k being sold for $279[2] when you can get a similar performing current gen i3 for $115[3]