And I see where you're coming from, if someone else buys something, why should a different person care? It doesn't affect them right? But then that's the issue. It does. £799 1080tis selling fairly decently shows confirms to Nvidia that they were right to price it that high and next time round, they would be confident to price it even higher.
If something sells well, then companies will want to repeat that success. What it would mean is that even at the low end, Nvidia will (and currently is) increase prices in the future. It's like video games that are broken on launch or have issues. They still sell tons of copies, so developers now realise that it's okay to continue to sell their products in that way. Now it's par for the course for games not to be working properly on release.
Meanwhile I spend a mere £50. And that was worth it too. It's not even about being able to afford it, cos I could also easily afford '£400 for Zelda'. It's just a matter of what each individual values it at. I don't think it's good value when I'm in a position where I can pay much less for the same thing. I will admit though, most folks don't have the choice for only £50 like I did.