Cheap pads

My pay has now been halved due to a prolonged absence and when I go back I am going to have to go part time until my employer gets the neurology report, which I assume means part time pay. I finally got an appointment with the continence service whom I hope will provide me with pads on prescription, but thats not guaranteed. It is costing £12 - £15 per week for supplies over the counter. Is any supplier known to be particularly good value?