Someone will correct me if Im wrong but, that looks like Devilsyam main bike before he passed. His family must be selling it on, what i don't understand is why they didnt come on the forum and offer it here first. That bike is a part of FOC-U history.
Regarding the price, while it is a very trick bike with single sided swing arm and rim disc brake, as @Gnasher would say these trick bits do not increase the value of the bike if they are replacing existing parts. A 2001/25k FZS in good condition goes for £2000-2600. So this dealer is essentially asking £3600 for custom front and read ends, and some other parts on a bike that is in average condition, in fact it needs a proper valet which the dealer or the actual owner should have done before putting it up for sale.
Regarding the price, while it is a very trick bike with single sided swing arm and rim disc brake, as @Gnasher would say these trick bits do not increase the value of the bike if they are replacing existing parts. A 2001/25k FZS in good condition goes for £2000-2600. So this dealer is essentially asking £3600 for custom front and read ends, and some other parts on a bike that is in average condition, in fact it needs a proper valet which the dealer or the actual owner should have done before putting it up for sale.