line item progressive fee

[JasonE72]

So I have basic excel skills and I am trying to create a fee calculator. The issue I am trying to research is  that one item is $50 and everyone after is $40. How do I do create a formula for that in one line item?

[#2]

@JasonE72 

Let's say you enter the number of items in A2. The fee (for example in B2) is

=IF(A2=0,0,40*A2+10)