The Megillah states that Haman gave 10,000 Talents of silver to King Achasverous.
What is the value of a talent of silver in their age and the value now?
Jewish Encyclopedia writes a heavy talent was 60 kilograms, a light talent 30 kilograms, and there's an opinion (very bottom) it is 20 kilograms. 10,000 talents would then be between 200-600 tons of silver.
At today's price of 500 USD/kilo of silver this would be between 100 and 300 million dollars.