Calculating price by size of pipe and quantity than ranges in price per amount and size

I am trying to solve this for a friend. She and her husband run a plumbing company and sell pipe

pipe size Amount Units Price
0.75 100 5.3
0.75 300 5
0.75 1600 4
0.75 1601 3.9
1 100 5.3
1 300 5
1 1600 4
1 1601 3.9
1.25 100 5.3
1.25 300 5
1.25 1600 4
1.25 1601 3.9
1.5 500 5.1
1.5 1000 4.7
1.5 1001 4.1
2 500 5.1
2 1000 4.7
2 1001 4.1
2.5 500 5.1
2.5 1000 4.7
2.5 1001 4.1

What I am trying to do is create a formula for example, I want 1.5" pipe and 625 pieces pf that pipe. I would like the answer to be 4.7. This one has perplexed me to solve. Any help I would be much appreciated. Thanks.

Thank you NFL Sales. I have two tabs. Sheet two and Data Source. Sheet two is where the work order would be sent to the client on row 39, column G&H . Data Source tab has the pricing and other information. I wrote some information in the tabs to better explain what I need. Thank you. Brad

You're a genius. Thank you so much!