You should respond as you would to any other gift, with no more or less enthusiasm. There is no reason to refuse the gift on the grounds it is “too much.” If you have reason to believe someone may bring an extravagant gift, that could be reason enough to open presents after guests leave, so that other attendees — adults and children alike — don’t feel inadequate. When the gift giver reciprocates by inviting your child to a party, do not feel obligated to match the price of the present. Stick to your gift budget as you would with any other child.