find and select all instances of value in a column, perform calculation and return result

Hello!

I am trying to set up a macro that will run on the click of a button. I have two columns of data that will be used. I want to be able to type in a cell (lets say I2) the value that I am searching for, type in a cost in I3 and have the macro find all instances of the value in I2 in column A, take the corresponding value of column B for all those instances and add what I typed in cell I3, returning the result in the cell that is next to those results in colum C. I am new to recording or writing macro and would really appreciate the help![table="width: 500"]

test.xlsx