Budget a music festival weekend.
Festival budgets fail because the ticket is the only number anyone remembers. Accommodation multiplies by nights, food and drink multiply by days on site — one more than the nights, since you eat on arrival day and departure day — and travel is a single fixed block. Laying all four out shows that the ticket is often under half of the real weekend cost, and on-site food and drink is usually the runner-up.
Weekend total
Total = ticket + nightly rate x nights + daily food and drink x (nights + 1) + return travel
Daily burn
Cost per day on site = weekend total / (nights + 1)
A three-night festival means four days of eating — you arrive and eat on day one and still need breakfast on the departure morning. Using nights alone systematically underbudgets food.
On-site drink prices, locker or charging fees, and the cost of replacing camping gear. Building a ten to fifteen percent contingency over this total is sensible.