Whoateallthepies, a fixed wing licence can only save you a MAX of 6 hours towards a PPL(H). So, that 6 hours at £250 versus 45 hours at £100 per hour! Whirly's right and I'm appalled that a school would suggest it.
I've never flown fixed wing - don't think it's done me much harm!
However, I have heard that the following MAY be feasible IF you plan to do an iinstrument rating and do already have a fixed wing licence.
Get a fixed wing instrument rating and convert it to heli IR. I've not done the sums as it's not applicable to me but it may be a cost effective route for some.
Cheers
Whirls