Components
- Transport: $1360
- Accommodation: $250
- Food: $275
- Communication: $60
- Entertainment: $60
- Goods: ???
- Shipping stuff home: $80
Total: $2085 plus whatever we spend on goods.
Transport
- Airfare is $1275.96
- Not buying JR pass
- Expect to spend 750 yen per day, over 10 days - 7500 yen
Call it $1360 for now.
Accommodation
Airbnb - https://www.airbnb.com.au/rooms/1917112?checkin=08-02-2014&checkout=17-02-2014&guests=2
- If we can get this, it's $251.50
Estimate $250
Food
Guessing $25 per day.
Estimate $275 after adding some fudge factor.
Communication
Phone rental and data SIM purchase?
Maybe $60 depending on how we do it.
Entertainment
Mostly arcade games and anything to kill time.
Estimate $60
Goods
- Otaku goods
- Cosplay goods
- Souvenirs and stuff that people requested
- Some may be repaid later
Impossible to estimate, assume hundreds of dollars 
Shipping stuff home
Call it $80 for now, may not be necessary at all.