Uniform Allowance - Formula for Totals in Excess of Allowance

I am creating a uniform allowance spreadsheet to make tracking employee purchases simple.

Data

Allowance: 150
This is the amount of money the employee is entitled to for uniforms

Price:
This is the actual price of the uniform

Employee Cost:
This is the amount billed to the employee. They are billed anything over $150.



My problem is how to set up the formula for Employee Cost. I have Allowance in A6, Total Amount Purchased in G25, Price in G3-G23 and Emplyee Cost in H3-H23.


Thanks so much in advance ... this has had me stumped for awhile!

Thank you for trying! I knew I'd leave something out! Sorry!

A6 is currently set up as the allowance MINUS G3:G23 so that the value in A6 (originally 150) will reflect the amount of the allowance LEFT at any given time and each line G3:G23 is a different item of apparel, with an individual price and thus, an individual amount to be billed to the employee. It's because of this always-changing value that I'm having a hard time figuring a formula for Employee Cost, as I can't identify a constant.