A nVidia GForce GT580 was less than $500 (like $400), and a mid-to-highend GT570 around $250. The same class of cards the GTX 1080 costs now $650-$700 and the GTX 1070 $450.
"GTX 1070 prices start at $429 instead of $379, while GTX 1080 prices start at $649 (and if you actually want a card in stock, that’ll be $699). These are prices that are closer to last generations GTX 980 Ti/980 prices than they are 980/970, and it means that the actual GTX 1000 series price premium is much higher as it stands, at $100+ compared to the last generation. Given that these cards keep selling out, clearly there are enough buyers willing to pay these prices – it’s the free market in action – but it means NVIDIA’s MSRPs are for the moment an imaginary number."
Fact is computer components got more expensive, as less people buy a PC. It correlates with the stagnation of single core performance of Intel/AMD (aka no need to replace a years old PC at all) and the less than inviting situation that Microsoft introduced with Windows 8 and continues even more aggressive with Windows 10. The users simply buy an iOS or Android tablet and a Playstation 4 to prevent continues frustration.