What platform is this suggestion for?: Survival Server
By using the command /market or /bazaar will teleport you to a market place with a bunch of npc's. These npc's will allow you to buy a items for a set price, the transaction can be done either through certain blocks (iron, diamond, or netherite) or though the in game money system. There could also be a sell npc which would allow for players to sell there blocks for a set value, there could also be custom npc's that come at certain times and have custom items to sell and have a certain stock. In this place there can also be mini games, some ideas are like /arena in prison but single player and the longer you survive the more money you get (the armor is what they come with so no set armor for everyone), there can also be a archery game with multiple people where there is a mob on a mine cart and the first person to shoot the mob gets money. I feel like this would get the community to see each other more and interact because the only other time I see anyone else is if they are a team member and they come online or if I'm using the public xp farm, other than there is no spawn for everyone to chill at and meet people.