There was a grand total of one new RX 5700 XT available for sale in my country last week, Gigabyte, and it was priced at $1010. Now it's no longer available - someone bought it. I bought the exact same one from the same shop the week before for $758. Today I ordered a RTX 3060 Ti for $919 (free local shipping) and I'm happy I was able to get one.
RX 5700 is EOL and you can't buy them anymore.
I'd be willing to go down to $850/$800 but that's it. Not a dollar less.
Good luck with your sale. You are comparing new card prices with your second-hand one.
I can find multiple RX 5700 XT used between 600 and 750 USD in Serbia.