Work out what a trip will really cost

Work out what this trip is likely to cost.

Trip: two weeks in Japan next April, Tokyo and Kyoto, flying from Manchester
People: two adults
How we travel: cheap beds, spend it on food
Already known: flights are 720 each, already booked

Give me a table, one row per line of spending: flights, beds, getting around locally, food, tickets and entry, sim or data, insurance, and a row for the everyday bits people forget.

For each row give a low and a high, not one number, and say what the low assumes. Then a total range at the bottom.

After the table:
- Which of your numbers you're least confident in, and why
- The two or three costs people most often underestimate on a trip like this
- Anything that gets much cheaper if booked at a particular time

These are estimates, not quotes. Say clearly where prices move a lot by season or by how early you book, and tell me which numbers I should go and check myself before I rely on them.

What you get: A costed table with a low and a high per line, and a straight answer on which numbers you shouldn't trust yet.