Well thanks to the wonders of technology and the internet, there are in fact several ways you can get cash for your gift card.
List of Ways to Sell Amazon Gift Cards for Cash
15. Try a CoinStar Kiosk
21. Exchange it for Cryptocurrency
22. Check Back With Amazon
23. Use It, Sell the Items for Profit
24. Gift it to your Friends & Family.
25. Buy Stuff You Really Need