My understanding, at least in the past, is that it's the same hardware with different drivers. The drivers "guarantee" accurate rendering at cost of a bit of performance (maybe). At one point there were even hacks that allowed you to install the Quadro (it's quadro btw) drivers on gaming cards.

The extra cost is mainly from getting the cards/drivers certified by every CAD/CAE software vendor as compatible, and possibly just extracting extra value from a market perceived as less cost-sensitive (ie, they are probably paying 10k/year at least just in CAE software licenses).

They are and they might be a tiny bit slower than their gaming tuned counterparts, but they are still capable of running games without issues.