It always comes down to gold per minute unless there is exclusive loot. Here is an example of something that might not be too hard to implement but people would like. Rare blowing horns that come from trade routes only. Activate the item to make a loud noise, give it an hour long cooldown to prevent abuse. An example would be a Tribelands blowing horn. Alternatively, trade routes could give new materials to make special items like this and the recipes could be added to woodcutting. And here is the important part: Sure, these make great cash shop items and money is vital, but the game needs to have actual cool things you can farm up, otherwise it's always going to be about gold per minute and people will never be happy with many activities and monsters.