Need help adjusting settings for “Quantity Step”

We would like to have it so customers can buy in increments of 5.

5+ balls @2.99 / ball
10+ balls @$2.49 / ball
15-50 balls @ $1.99 / ball
50-100 balls @ $1.79 / ball

What are all the settings we’d use, to set this up?

Here are our current settings:

Fields:
https://app.box.com/s/rk0xqqdewgy76sgyfdxb7losuo5xdjrn
Add Options:
https://app.box.com/s/08j329lgsgu5xnr7ilnb8l7c68iucrh2

The page I need help with: [log in to see the link]