How to buy euros: Save enough for a decent dinner for two

Comparing rates to find the best deal can be confusing, because foreign-exchange dealers use a variety of propositions

Taking note: the cost of €500 varies sharply (AFP/Getty)

The seven-year-high at which sterling finds itself against the euro is spectacularly easy to squander.

The fastest way to do so? Walk up to a bureau de change at a UK airport. At Edinburgh this week, buying €500 cost £408, a rate of just €1.23 per £1, compared with the "spot rate" (the market mid-point between buying and selling rates) that touched €1.42on Wednesday.

You will never be able to change at exactly the spot rate with a financial provider, though if you have many millions you may get close. Most of us are interested in modest sums for taking on holiday rather than speculating.

Comparing rates to find the best deal can be confusing, because foreign-exchange dealers use a variety of propositions. Some impose commission, others do not, and rates may vary according to how much you want to change.

The only way reliably to compare banks, travel agents, the Post Office and online providers is to ask: "how much will it cost me to buy €500?" (or whatever amount you need).Then you can pick the lowest figure.

My bank wanted £371. Marks & Spencer and the Post Office were equal at £369; but if you spend £400 or more, the Post Office will deliver the cash free to your home.

Booking online at ICE (iceplc.com) for home delivery costs £366. The same company has an interesting proposition: search online for "ICE voucher"; print it out (or download it) for a specific location such as Edinburgh, Gatwick, Heathrow or Luton airport and you get a better-than-walk-up rate; €500 cost £363.

The best rate I found on Wednesday this week was at Thomas Exchange Global, which has eight offices dotted around London. Again, you get a better rate if you reserve in advance online at thomasexchangeglobal.co.uk. The cost of that €500 fell to just £357. The saving over the figure Edinburgh airport first wanted added up to £51 – a decent dinner for two.