TheNavigator,
my training provider (Ravenair at Liverpool) offer a few options:
1) Pay-up front for the best discount.
2) Pay £1000-00 up front for 10% discount off everything (including landing fees)
3) Pay £3000-00 up front for 12% doscount (not absolutely sure about this last one)
I opted for the £1000 since it gives me a good discount and reduces the amount of risk I am exposed to should Ravenair go bump.
p.s. Ravenair have been great upto now, would recommend them to anyone.
(And no, I don't work for them or intend to in the near future).