VLOOKUP to return sum of cells?

Good evening,

I am looking for a VLOOKUP or similar to return the sum of all associated cells.
I have a spreadsheet of products that my company produces, in column A is the 'part number', column B lists all materials that are associated with that part number, column C details the cost of materials in column B.

What I would like is that when somebody inputs the part number into a defined cell, it will return the accumulated costs of all cells in column C that match the part number in column A.

I have attached test data for reference. In this example Sheet1 holds the data, Sheet 2 cell B1 is where the user would input the part number they are searching, and the sum of values would be returned in Cell B2 on sheet 2.

I really hope this makes sense. I'm happy to clarify required.

Thank you in advanced.

Kind regards,