Completed for X3: https://www.ebay.com/sch/i.html?_from=R40&_nkw=Antminer+X3&_sacat=0&rt=nc&LH_Complete=1
Completed for L3+: https://www.ebay.com/sch/i.html?_from=R40&_nkw=antminer+l3%2B&_sacat=0&rt=nc&LH_Complete=1
So they are selling and moving. Even with the 15% cut that eBay / PayPal take you can still make some money on them.
Opinion: I would sell the X3 1st it's worth more, generates less, has fewer coins to mine and if at any time the few that use the original cryptonight decide to fork a bit the value can drop like a rock.
There are about a billion scrypt coins out there, and the L3+ is worth less anyway. It's price on eBay has stabilized for a while now so unless something radical changes what you can get today you can probably get next month or the month after that.
-Dave