Well, you want to future proof your PC for the next ~5 years and then manage to run everything at high settings? That's not really economical as to future proof requires the purchase of the most cutting edge hardware on the market, which happens to be extremely expensive. It might be cheaper to upgrade parts every 2 or so years. But if you want to last with the same build for 5 years, running next gen games at higher settings than even next gen consoles, then you're looking at maybe a $2000 PC. What ever GPU you purchase should have at least 3GB+ GDDR5 memory (maybe 6GB if you want to be guaranteed future proof - Radeon HD 7990 or Titan.. maybe those two are already overkill idk haha). And maybe you should go for AMD (as thats what consoles are using). Otherwise, a $700 PC Build could get you through nextgen if you're ok with medium-ish settings (PC hardware has simply eclipsed consoles in recent years, where in the past consoles were usually ahead of PC's for a good couple of months, the next gen consoles are already behind the best of PC's).