I would suggest three things
1. Have the xbox marked as a gift - total value $0.00
2. Have it marked as a computer as it is a computer running a different os.
3. Looking at the tariff tables be prepared for the following
950450 Video game consoles & machines, other than those of subheading 9504.30 - 40% duty plus 15%vat
950410 Video games of a kind used with a television receiver - 40%duty plus 15%vat