treasure, assets, pay a fine
貲 centers on wealth in the form of money or goods: treasure, assets, and the act of paying a fine, which is a forced transfer of wealth.
貲 combines 貝 (shell, money) with 此, which likely contributes the sound. The character originally referred to wealth or property, and the fine sense developed from the idea of paying with assets.
The top 此 looks like a stack of coins, and the bottom 貝 is a shell used as money. Together they represent treasure or assets, and paying a fine means giving up some of that wealth.
For シ, imagine a sheikh counting his treasure: sheikh -> シ, and his assets include piles of shells and coins.