Yes actually it is.
If you plan to travel for a year in the western hemisphere it makes more sense to buy a new Honda in the states. In the U.S. the CRF250L lists for $4499 new which is about £2830 in your money. It would cost a lot for you to ship it across the pond at the end of your journey if you traveled North, Central and South America for a year. No need for a carnet in this hemisphere so that would save some money and hassle. But import duties may negate any savings. I have no idea. It might make more sense to sell it at the end of the year and fly home.
The UK is probably the cheapest country in the EU to buy a bike. The CRF250L sells new for around £4000 or around $6350 at current exchange rates. If your travel interest is more Trans-asia or Africa, it probably makes more sense to buy and prep the bike at home.
If money is tight and you have good negotiating and mechanical skills, it is much more economical to buy a good well cared for used bike. You can find good deals on used bikes in any country.