just stumbled across someone in trade chat who was selling a crafted BOE gear that was already upgraded via Valor Points (was 1/2 and had iLvl 500) but still showing as "Bind on Equip". Not sure if this is really possible or only showing as BOE when posted (and I didn't want to waste my own VP just to try). I also don't know if this is intended by Blizzard and will stay like this. But since VP is one of the most precious goods, due to the weekly limitation, I think it can be quite nice to have other people spend their VP for upgrading your chars items for some coins (because you know, money doesn't matter for us in the end).
Just wanted to share this with you. And if anybody wants to try to upgrade a BOE item and see if it remains BOE, please confirm back here!
At least I myself am eagerly willing to pay some gold to get BOE's upgraded for my chars.