Group Threshold Algorithm (Single Item Priced)
This method gives the higher price for the single item until the last item in the deal.
Example
3 for $1.00 is priced at $.34, .34, .32
5 for $.88 is priced at .18 for the first 4 items, and .16 for the last
7 for $1.00 is priced at .15 for the first 6, and .10 for the last.