Here’s my used electronic GX AXS derailer from a couple years ago still works great I just upgraded to XX1. No battery, got a few scratches on it from regular use but works great. Sold as is free shipping. 
Used Shimano Dura-Ace RD-7700 rear derailleur. Body and knuckle have heavy crash rash with deep gouges around the Dura-Ace logo and on the outer link, plus scratches and scuffs on the cage and hardware.