Cost Calculator

I am trying to create a simple cost calculator

Col a - Col b
Value Premium

e.g.

Col a - Colb b
120 - 50

col b needs to find the range

eg
1 - 50 = 10
51- 100 = 20
100 - 150 = 50
etc

I tried to attach an zip example but for some reason I canot attached it

thanks in anticipation

Is this what you're after? (See attached zip file)