how to add extra fee per # ordered

[CheapStairParts]

How do I add an extra fee every time they order 1-4, 5-8, 9-12.. ect.

so if they order 1 through 4 it adds $25

if they order 5 - 8 it adds 50 ... 9 - 12 adds 75.

any clue?

[wolfsz]

Hi there
Is this for transport? If so could set your shipping fee to $25.00, which would cover you for 1 - 4 units. For the increments you would then need to edit the flat fee shipping module. I have never used the Table shipping module, might be worth investigating.