Quoted from underlord:
That's the issue. Lots of used pros, even a good amount of nibs.
If demand was overwhelming, these would be sold quick.
Supply is up because people still want 5K and up. If it's like IMVE, you can get a brand new one from a reputable dealer with extras for about $4700 shipped. Let's not forget that the specter of VE's is another reason why the supply of used ones is up. Any of these sellers need to come down to about 4K to sell. Otherwise, while they're officially "for sale", they're not really for sale.