Well, it will be pretty tough for Prolific to compete with Jim's treasure chest. I think Jim might rename the Freshwater to "SereneScreen Treasure Chest Aquarium" because of the time he has spent on it.
And from what I hear, this is not folly and worth the time spent!
Considering there may be a mermaid saver from Prolific, I think the rules are a bit more relaxed on OPTIONAL "toy" items.