INDEX MATCH MATCH multiple columns with same heading

Hi,

I am a new user and I have recently started a job in finance where I am getting the opportunity to become a power user of excel, unfortunately there aren't always people here to help me answer my questions. The error I am having today is a INDEX MATCH MATCH problem, when trying to put data into a more manipulatable form I need to run a index match match query. The problem I have is that there are repeats in the column header, so it only picks up the first instance , runs it to the bottom and then doesn't run it again. I have made up a simple spreadsheet that explains my problem, the original data is massive, hence the need for a formula. Using the example I have uploaded, I need a formula that will count all of the John columns, not just the first one.

The Three column table is what I need to populate so it can be manipulated more easily using other functions, as you can see the total sum of the 15 column table is $335, and the sum of the cost column in the three column table is $253.