I would like to add discount to an order, but the tricky bit for me is the following:
1 photo = £15.00
But for every 3 photos i want to subtract £3 and for every 3 photos after that another £3 off the total order
So 3 photos @ £15 = £45 - the discount (£3) gives me a total of £42
And 6 photos @ £15 = £90 - the discount (£3 x2 = 6) total of £84
and so on...
But i only want this to happen after every 3 photos if you get me?
If anyone can help it would be greatly appreciated!