Those buying used desktop GPU's for high prices right now: why?

I have been watching some local stores and it seems that laptops have the Max-P variants of the 30X0 series, which outperform a lot of the older used desktop GPUs that people have been buying up on eBay or on Reddit - at prices that are close to the entire cost of a new laptop. What's the deal with that? Is there something to do with mining or something that I'm missing?

Sometimes its unique circumstance but most the time i think it might just be people not looking into what they're getting.