Which is more expensive shrimp or scallops?

Could you please elaborate on the factors that contribute to the pricing differences between shrimp and scallops? Are there specific factors such as demand, supply, seasonality, or quality that play a significant role in determining which seafood is more expensive? Additionally, are there any regional variations in pricing that could affect the comparison? It would be insightful to understand the nuances behind the pricing dynamics of these two popular seafood options.