Well........you get what you pay for ( unless it's got HK on the side of it )It's amusing to me that XDs, subsequent to being marketed by Springfield, are now more expensive than Glocks. $400 is my "standard" price that I'm willing to pay for a lnib Glock, sometimes even get night sights @ that price.
Here in Maryland a brand new XD-45 compact black is worth $599.99 + taxes and other expenses. So $400.00 for a used one is certainly a good deal for me. Rest depands on the condition of the handgun.Here near Seattle, prices are higher than most places. I've seen brand new XD .45 Service black/black for $435. Most places it's $455. 9mm lower.
So, to ME $400 used doesn't seem like a deal but it's not far off.