The Roll20 marketplace is really terrible. You'd think they would be motivated to help people who want to give them money do so, but not the case. I'm baffled as to why you can't search by intended level as well as system. As a GM buying adventures, I would always have a particular gaming system in mind and either be looking for a full campaign or an adventure for an existing party, but you can't look for all 5e adventures for 5th level characters or sort by intended level range. There's also no review system, so it's very difficult to tell what is amazing and what is garbage.