GTX 970 = 329$
GTX 980 = 549$
http://www.pcper.com/reviews/Graphics-Cards/NVIDIA-GeForce-GTX-980-and-GTX-970-GM204-Review-Power-and-Efficiency
http://techreport.com/review/27067/nvidia-geforce-gtx-980-and-970-graphics-cards-reviewed
http://www.guru3d.com/articles-pages/nvidia-geforce-gtx-970-and-980-reference-review,1.html
http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_970_SLI/
http://hardocp.com/article/2014/09/18/nvidia_maxwell_gpu_geforce_gtx_980_video_card_review#.VBzwOvldUqJ
http://anandtech.com/show/8526/nvidia-geforce-gtx-980-review
http://www.tomshardware.com/news/nvidia-gtx-980-970-maxwell,27707.html
GTX 980 = 549$
http://www.pcper.com/reviews/Graphics-Cards/NVIDIA-GeForce-GTX-980-and-GTX-970-GM204-Review-Power-and-Efficiency
http://techreport.com/review/27067/nvidia-geforce-gtx-980-and-970-graphics-cards-reviewed
http://www.guru3d.com/articles-pages/nvidia-geforce-gtx-970-and-980-reference-review,1.html
http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_970_SLI/
http://hardocp.com/article/2014/09/18/nvidia_maxwell_gpu_geforce_gtx_980_video_card_review#.VBzwOvldUqJ
http://anandtech.com/show/8526/nvidia-geforce-gtx-980-review
http://www.tomshardware.com/news/nvidia-gtx-980-970-maxwell,27707.html