This Khul’a is void and has no value! one must stay away from such people, who claim to have authority to divorce a married couple! Such contract can only be done in a country ruled by the Sharia and by an Islamic Judge. If it’s done in an non-Muslim country, then the head of the authorized Islamic Center must be consulted. For 50£, this man is cheap and must be a millionaire by now!
And yes, the husband must agree to the khula.