I’ve played this game a few times and bonus’d it a few times too. But every bonus has been like £30-40 on a £2.50 stake.
the issue for me is you rarely get any base game wins to tide you over so it just eats money while you try and build the meters.
I’m not a fan of the ‘build’ games as i just feel like im ploughing cash into getting a good bonus, and if i get a bonus i know it will be sub par as ive not built it up enough. I felt the same about kingmaker too