The cheapest advertised flight or room does not reveal the total trip cost.
Separate fixed and daily costs
International transport, car rental and major rail or ferry bookings are fixed; meals, parking and attractions accumulate daily.
Budget for distance
Fuel, internal flights and one-way rental fees can dominate a multi-region trip.
Taxes and tipping
Displayed prices may not include all sales taxes, and tipping customs affect restaurant and service costs.
Use a contingency
Weather changes, missed connections or an extra hotel night should not destroy the budget.