I would like to request a custom shop npc.

What I suggest is players get a "work order" item from the Mayor that's already in the mod.
They right-click the work order to open a gui that allows them to set what their shop npc will buy and sell, and for what prices.
In order to hire their shop npc they have to click "confirm" closing the gui.
Then they can place (and shift+place to confirm) either on the ground, or possible on an inventory of some kind.
Players will need to provide an inventory to hold the stock for items they sell,
to hold the items they buy, and a place to store the harvest festival money their shop uses (cash register maybe?).

Possibly having a new "shop" build specifically for this custom shop npc.
At the very least allow the npc to be place by players in their own building without needing to spawn a full shop and redesign it.
Maybe have a cash-register block to hold the money, and some kind of display case to hold the stock being sold?
At least have the cash register block for holding the player's shop's harvest festival gold.

This should be easy enough to adapt to other types of custom npc's.

@joshiejack perhaps you could hook into the Custom NPC's mod to make it easier to add this?

Adding Custom NPC integration would allow for this and so much more.
And should make it a lot easier to seemingly implement this feature.
#86