Vault is a town only function. The only reason it was free and we were able to use it in the wild was because of the reset. People needed a way to get their items into town before the reset, so Justin was nice and allowed this for a week or so.
Opening the vault in the wild without any transition fee was a perk during the non-town worlds reset. It was stated in the changelog.
Ooooh, usually im up to date on these things but i guess i wasnt paying all that much attention, Thanks Zabriel
Awww its ok, people miss things sometimes I wouldn't worry too much about it, a lot was going on the last couple weeks with upgrades and resets and whatnot.