This is a math problem in primary school. Want to ask a math problem or know which one saves money? The cost of 30 copies is the same, and more than 30 copies are cost-effective. But if it's not a math problem, there are other components in it, involving later reimbursement and lettering. If you can engrave in the future, you can buy your own burner, which is only over 100, and the disc is only over one yuan, which is not so expensive.