Yeah i'm confuse too, i don't see the rapport between an house ("vanity", +value) and the game himself (pve/pvp) where stats is the most important.. We have here same reactions with the flounders helm (vanity) and his 5dmg 5armor on PL.
The good way will be: make locations tradeables (or another way will be delete buffs).

I prefer this one because it add a new challenge: own a tavern and locations .

The dream will be this way with a UNIQUE house, one upkeep, for all your toons. We all are probably pretty sure noone will decide to buy 3taverns for each toons.
The sad way if you don't change anything will cause frustration for players who decide/ed to own few platinums.