GameStop currently has a bonus $50 trade in on XBox One and a $175 Trade in Credit for PS4 systems. Multiple XBox One systems are also on sale making it possible to upgrade for $100.
GameStop Trade-In Info: http://www.gamestop.co
For example a XBox One 3 Battlefield 1 500Gb Console is on sale for $250 – $150 Trade Credit – $100:
http://www.gamestop.co
Check their site for more deals.