Sorry New Bloke, the CAA have happily prosecuted for less than that.
The limitations of a PPL are something like:
No hire, reward or valuable consideration.
Cannot provide a service
Cannot do aerial work.
The only let out is the Charity Flight exemption, if you can't meet that requirement the option is take 3 months off work, stump up £10,000+ and get a CPL (you still need a PT CofA though).
I don't like to put a damper on anyones flying ambitions, but you never know whos watching.