Sorry if I didn't make myself very clear!
OK, so I have a basic store with over 100 products all with a flat rate of £8 shipping.
What I'd like to do is offer 4 of those products with a cheaper delivery option, say £3.50. One of the 4 cheaper products I'l like the customer to be able to order up to 12 of them and or any of the other cheaper delivery products but still only charge £3.50 in total.
If a product that is not a part of the cheaper set is added then the deliver charge should be £8 total.
So never more than £8.
This may seem really obvious to someone of experience but it's baffling me.