Looking for a woocommerce plug in

Help
does anyone know what its called when you have on a shopping cart when you can sell quantity breaks like t-shirts
example
1-12 @ $15.00
13-25 @ $13.50
26-50 @ $9.99
Ive heard it called dynamic pricing but Im not finding a plug in that works with woocommerce that will allow us to input fixed pricing? Example the 13-25 price goes into the shopping cart?
HELP>>>>>>>>>
Or
Have 4 different prices in the same product listing?