How much silver did Haman offer to pay into the royal treasury?

Answer: 10,000 talents

Haman offered ten thousand talents of silver to pay those who would carry out the decree; the king told him to keep the money.

“If it pleases the king, let a decree be issued to destroy them, and I will deposit ten thousand talents of silver into the royal treasury to pay those who carry it out.””— Esther 3:9 (BSB)