I would be more for a mixed solution, mostly based on
this thread. Boston stays as it is, but teleport is removed and the rent on the Boston stalls is lowered. Villages can build stands that are fueled by authority, but the mayor can set a rent and special permissions to use them (they may also be usable by strangers). The items available from the npc stalls can be bought also from the homestead, with an additional fee for "delivery" (maybe something like a mailbox could be necessary for this, though). This would be true for mail and silver retrieval from the bank as well, anyway. Villages could be able to build Hudson Bay Company offices. Doing so gives the builder a "proposal of contract" that can be given at an npc in Boston to settle the contract (npcs would then appear in a short while, thus giving the functionalities of post, npc stall and silver retrieval that are available in Boston, but just for villagers). Obviously the office costs authority for maintenance.