1080Ti on amazon already selling for $600 (RX 580 for $200), so I am sure gamers will not pay over $300 for Ex miner 1080TI GPU's, and now think for how much they gonna sold in few month when RTX will be out, and AMD 7nm around the corner, the 2nd hand market is flooded with mining GPU's and it hard to sell now and in future so any1 that didn't ROI until now should really consider Selling the GPU's, they are loosing more Value per day on 2nd market then they mine.
The $$$ from selling the GPU's will "Mine" more coins then the GPU's could in Years.