Hard to judge what they are selling for. I see regular xd for 500-500 but as low as 350. The xdm as high as 800 but who knows that it's gonna sell there. But mostly 550-700. Have yet to figure out why they swing so far for the same thing. Glocks are pretty competitive within 50 usually.
What are they selling for on GB new? Whatever that number is, expect to sell for less. XDMs dont seem to be in short supply or high demand so your used price is gng to have to be better than new price to entice a buyer. I wouldnt count on the OD fetching anymore $. If anything the OD probably reduces number of potential buyers. I paid $325 for a used full size XD a few years ago but that was an XD.