Hi Manj,
Taking a test on your old Excell worksheet I could see that by leaving value fields empty, the Order Total is still 13.176.
You should check your new worksheet leaving empty the value fields and see what happens. If the total is not equal to 0, you should configure your Excell worksheet in order to get the resul that you want.
To hide the default price on a single product page you can use CSS for example.
To set a message instead of price, you have to edit some WooCommerce core files and not WooCommerce calculator files.
Regards,
Riccardo