I know the auction house has been suggested but I think that's boring compared to the shop economy we have now
My suggestion is have the server reserve an area for a marketplace with stalls, allow the stalls to be rented out like a flea market. The stalls could just be a set area that's blank and people could build and decorate their own storefronts. If you put the stalls together you could also have the option of renting stalls that are next to each other to have a larger shop. This could also make the server feel more alive as the common shop area would be an easy place to see other players going about their business
My suggestion is have the server reserve an area for a marketplace with stalls, allow the stalls to be rented out like a flea market. The stalls could just be a set area that's blank and people could build and decorate their own storefronts. If you put the stalls together you could also have the option of renting stalls that are next to each other to have a larger shop. This could also make the server feel more alive as the common shop area would be an easy place to see other players going about their business