What does the £2500 you've quoted include? I guess its some sort of package including some sim time, a couple of hours brush up on the aircraft and a test? It sounds a little steep.
How current are you? If you are in recent flying practice, I would suggest an hour or two refresher in an aircraft, followed by the test should come to about £1500 ish. (3 hours twin hire, examiner fee and approach/landing fee's)
Have you shopped around a bit in the uk. Just a thought.