Possible??? - Multiply Individually, then Sum, for an entire Range

Hello,
I am trying to build a spreadsheet to track inventory at a consignment store. I've attached a picture of my spreadsheet for visual reference.
At the far right, I am able to total the revenue I receive (70%) for each item in the row, and then get the sum total for the whole column at the top in row 1
I would like to calculate my 70% total for each month so that I can easily roll that into my master summary spreadsheet.
To do this, I would need to multiply (for October) N4*$C4 for each row, and then sum those totals.
I could insert a new column for each month to achieve this, but i was hoping there was a formulaic way to do this so I could have the 70% revenue total at the top above each month, without having to add extra columns.

While there are only 12 different items right now, the list will grow, so i dont want to have to manually add each calculation.
(N4*$C4)+(N5*$C5)+(N6*$C6)+(N7*$C7)+(etc etc)
Is there a formula that can multiply the range in column N by the cells in column C for the same row, and the Sum them, without me having to manually write out?

Screenshot 2025-01-21 143202.png

If I understand, that looks exactly like a SUMPRODUCT() function: https://support.microsoft.com/en-us/...c-4d2145a2fd2e =SUMPRODUCT(N4:N40,$C4:$C40)