Right now I got an RX 460 w/ 4gigs, on my MS 7751 with an i5-3570k, I also have a 500w power supply. I'm looking to upgrade to something a bit beefier. I'm looking for something around $300 or less and have been think of a Gigabyte Geforce GTX 1060 G1, but interested in some options. Also, my current card isn't that old, anyone know the best way to sell it outside of eBay?

Thank you for any advice!