Travelling to Gatwick to sit exams (train, car, bus or fly). Accomodation at Gatwick for each sitting. All adds up.
Do you plan on passing everything first time? Hopefully so but don't let your dreams evaporate because you didn't allow a bit extra to cover having a bad day.
Add on at least a 10% contingency to your total costs to allow for the unforseen. eg: spending more time on the ground not flying due to wx whilst racking up your daily fixed costs (accomodation/food etc).
And if you have a job before changing careers then your TRUE cost will be the salary sacrifice of not working whilst training.