well how else am i supposed to sell to willing buyers? no one wants to buy online any other way, you get assurance with ebay that you get the product or your money back.
It will be better to just sell it locally through Craigslist, might take some time since the consensus of most consumers is "PS4 is better in every way" but should not take too long.
If you want to sell it here
use the [WTS] in the title and post pictures of the Xbone with your physical evidence of your username in the picture (write your name on a piece of paper do not add your username with a photo editing program)