1. Mermaid tourmaline is a natural gem, which is rare and precious, so its price is higher. The cost of ice cream depends on its making materials and ingredients.

2. Mermaid tourmaline needs cutting, polishing and other processes to make jewelry, which takes a lot of time and labor costs, so the price is higher. However, the production process of ice cream is simple and the price is low. So the mermaid tourmaline is very expensive.