I have to say I am disappointed with my DC X11s. I paid 800US plus shipping and wish I'd paid the extra 200 US for the Bose x instead.
True, compared to the ASAs I used previously they are a big improvement. But the audio clarity and comfort of The Boses surpasses them easily.
I think it will be difficult to find a pair of secondhand Bose x as they are too good to be replaced.
Best,
Sicknote