I am SERIOUSLY considering seeing KAT-TUN in Tokyo Dome

Thinking of Going Thursday 19 to Monday/Sunday 22/23. I get back Monday 8am, get train back to uni in time for 1pm Japanese class.

Flights are around 500/600

Tickets is 6800 Yen.

Hotel Could Cost me about 100...

That's about 800pounds right?
What have I missed?

I currently have 300 and I get my loan 3 days before the flight and I have a 1000 overdraft which means I can pay for the flight and ticket before the money goes it and such... this is TOTALLY possible for me, but mother says no!!

Any idea where a foreigner can get KAT-TUN tickets? xD

AND my birthday is the week AFTER it so... early Birthday present?