Getsometimein,
Prior to Pay2000 we did not have an incremental pay system, it was a flat rate depending on rank, I don't recall that having an impact upon the recruitment of NCA or any other trade for that matter. How many civvy jobs have incremental pay?
The good news is, join at 18 as a Sgt, make it to MAcr and have a better pension than any other non-commissioned rank.
And it's still one of the best jobs the RAF has to offer!