[Powerlab]

Exactly, to do it as a hobby and maybe charge a few friends / family for a couple remaps on their cars you need atleast a reworked clone (£250 would be a realistic price)

then you need a good tuner, which vary largely in price

as 8baller says, at least you must have a good clone tool for not to have a problem.

after you can try to make money one by one for ppl around you to make more invest your hobby.