My advice:
1) Wait til 2016 when 14nm GPU comes out.
2) wait til 2021 when 7nm/5nm or graphene GPU comes out. GLuck.
Recommend option 2. Yes, you'll have to spend 6 years of your life before you upgrade...but who cares?? it's just 6 years. You see 6 summer, 6 Christmas, 6 thanks giving...before you know it, 2021 is here. If you're 24 now, you'll hardly get a wrinkle then. Again, Gluck.