At £10k - a cheap Bike..if you want one
(an expensive Bike if you don't and as most of you don't, it will seem expensive)
If he supplied the Bike and if HPN did the work it would have cost him at least £8,000 WITHOUT the engine and gearbox work, (which was done by Andrew Sexton).
From HPN - the WP front forks cost almost £2,000 and the WP Shock £600. The Tank is £500 and the rear swing arm £800 with a further £1,000+ to mod the frame and sub frame, then brakes, wheels, tyres, exhaust
If he started with a Basic I reckon it would have cost him, £14K plus, (all up with the original Bike cost) to build the Bike if he did not do any of the work.