Single post in Egg supplier fast-order

I think, to implement this, the discount would have to be calculated live. Live might not be the right word here, but it's the best one I can think of. Basically, as it is now, the system just has to have a tag of something like <price>-%per egg already ordered But for this to work--assuming I'm correct in how this stuff works--there'd have to be entirely new code (not recode the entire function, but an entirely new piece of code) that calculates it something like this: <price>-%per number higher than 1 and it'd have to be calculated "live" in a sense.