Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

How to model fees from trades on online platforms?
Assuming cell A1 contains the number of trades: will price up to A1=100 at 17 each, and the rest at 14 each. The key is the MAX and MIN. They keep an item from being counted twice. If X would end up negative, MAX(0,x) clamps it to 0. By extension, if X-100 would be negative, MAX(0, X-100) would be 0 -- ie: that number doesn't increase til X>100. When A1=99, MIN(a1,100) == 99, and MAX(0,a1-100) == 0. When A1=100, MIN(a1,100) == 100, and MAX(0,a1-100) == 0. When A1=101, MIN(a1,100) == 100, and MAX(0,a1-100) == 1. Of course, if the 100th item should be $14, then change the 100s to 99s.