One thing I dislike is the cost of lagoon decorations, as I always felt it was way too expensive compared to standard decorations. The standard cost of non-lagoon decorative items is $1,000, while lagoon decorations are $25,000.
When playing in sandbox mode, it really is not an issue as money could be toggled off, but in a campaign/challenge park scenario, the expensive decorations are a turn-off. I would often have barren lagoons in my challenge or campaign parks as I worry that decorating my lagoons would put me at financial risk.
For comparison, if I were to put in 30 decorations in a dinosaur enclosure or aviary, it would cost me $30,000 to do so. It does not cost much and the enclosure looks nice, with it being a fun way to pass the time waiting for research or other tasks to be completed. However, if I want to decorate my lagoons with 30 decorations, it would set me back $750,000!!! That is a lot of money to throw around for something surface-level with no direct benefit to the park's growth.
I would like for the price of the lagoon decorations to be reduced so that it would be motivating to decorate my lagoons without running the risk of losing money. Even at $2,500, it would be more expensive than standard decorations, giving off a more premium feel to these decorations, but $75,000 is easier to stomach than $750,000.