Seeking multibuy apps for repeat purchase discounts on a collection?

[spsabers]

Hi~
im looking for an app with the following function.
say for example i have items: Red, Blue and Yellow, in a collection.
I want an app that enables a repeat purchase discount that works as follows (numbers are examples only)

Customer order 1, they ordered item red (Full Price)
Customer order 2 , they order item Blue (save 10%)
Customer order 3, they order item Yellow (save 20%)

They could purchase mulitple of the same item also for the discount, so ideally the discount would be based on the number of items previously purchased from that collection
To encourage people to come back and order the entire collection, but get a discount based on the number of items for the collection they have previously ordered.