There should be a thing to spend in-game money to upgrade your island through upgrades such as hopper limit, mob limit, crop speed, spawner speed, etc. Each upgrade could be in 3 tiers increasing in price each tier.
Not quite sure, if these are medium-priced, sure. But this could become a negative for new players, yes they have to grind but the prices for /exploreshop was too expensive for the new players. Good idea though, this would be a place you can spend the money, maybe not a hopper limit though, unless you are thinking something different to what I am thinking. (X hoppers /island - Tier 1, Idk). Some thoughts.