Money doesn't need to be an object for groundschool.
The most you can pay is pretty insignificant compared to the flying training aspect. The most I ever saw it advertised was on BAe website (under the modular part) where they quoted in the region of £7K when converted at todays exchange rate; but I don't think they ever offered it as a standalone modular course, since dates were always marked as
TBD.
In the region of £5.5K is about the most expensive I've seen.