Create a new heading in your diary called Organising the information.  Create subheadings in this section.  These will vary depending on your possible holiday, they might include Food, Travel, Prices, Sports, Nightlife etc.

When comparing costs AND calculating the total cost of your holiday you will need to use a spreadsheet. Make sure you use features within the spreadsheet such as formulae, shading cells, formatting numbers as currency, adding borders and perhaps a formula calculating a deposit payment (say 8% or 10% of the total cost) in your diary.
 
A graph is also very useful. You might like to use a graph to show how your chosen holiday is cheaper than an alternative, or to show how the total costs breakdown between travel, food, spending money etc.  (You can do more than one, they are very easy to create).

Outcomes
  
Proof of all the features you used within the spreadsheet, screenshots in your diary of the spreadsheet showing numbers, displaying formulae, with the grid and column/row headings also displayed, and of the graph(s) you created.

Homework
  
You must complete your Organising section in your diary before next lesson.  Your teacher will be collecting a print of your diary so far at the end of next lesson.