Yes, Whirlygig is quite right. Save about £100k plus contingencies and it'll be somewhere near to what you need if you do it all in minimum times. Maybe I should write a book on how to go about it the cheapest way including all the pitfalls, scams, money saving ideas?
Could sell it for £50 a shot ( only 14 minutes in an R22 LMAO) so well worth the money.
from someone who has been there, seen it, done it, and now wearing the t-shirt (rubber suit?)