If he is SE & a Sole Trader the total cost of any tool he buys for his job can be offset against his tax liability.if self employed again as mentioned you could get tax relief on some of the tools and cloths and some prof registrations, not sure what the rules are these day - sure someone will help on current HMRC rules
Or put another way any cost relating to his business can be offset, however things like using the home as an office, laundry, work clothes, phone bills and a few others I can't remember have set allowances.
Advertising and registrations are fully tax deductible.
But, the OP needs to understand that if he pays £5000 in his first year for tools the HMRC aren't going to give him £5k back.
