How does this relate to my property purchase?
You have signed for a property, priced in Euros, that you have calculated will cost you £100,000. Will this be the same in two months time when you need to pay for it?
You have agreed to buy a house overseas. You need to transfer your deposit over immediately. You will want the best exchange rate!
You need to make 3 additional staged payments over the next 12 months. How much will these cost you in sterling? You have retired overseas. You know that your pension, paid in £'s sterling, will be £15,000 per year. What will this be worth in the country where you are now living?
You have agreed on a local currency mortgage to buy your overseas property and will be paying for it out of your £ Sterling income. How much will your mortgage payments cost over the next year?
Budgeting your expenditure accurately is impossible without knowing what exchange rate you will get to convert your sterling into foreign currency.