I'll probably have missed a few things, but whatever.

 * December 24 - Snacks: '''1001 yen'''
 * December 25 - Bread, gyoza, snacks: '''3459 yen'''
 * December 26 - Baumkuchen, waffles, drinks: '''2599 yen'''
 * December 27 - Coffee, KFC, drinks: '''2817 yen'''


= Sum total =
 * xx,xxx yen == AUD $yyy @ zz.z yen/dollar
 * yy AUD in stuff outside Japan

'''About $yyy in food all up'''