Another key factor will be how frequently you fly, I think it would be difficult to get a PPL in 45 hours if that was spread over say 2 years but very possible if you could do it over a few months as I did. I understand that 65 hours is becoming the average (I had previously thought it was 55) and I suspect a lot of that is due to extended courses (and older trainees?)
Don't forget landing fees away from base and possibly at base also ground school if you need it.
Agree with the others try for a C152 or a PA38, hire for a PA38 at EGBT would be c £15 per hour cheaper than a PA28.
I suggest you stick with FTO's at licensed airfields, if its unlicensed you will have to touch down at a licensed field to validate the flight and that takes time and money.
Why not ask for a detailed breakdown of the proposed course?
Good luck
(I don't speak for EGBT or the flight School I just fly from there)