Link webform to my paypal

I have a form that generates a total price based on what customer selected in the form. I need for whatever this total will be, to be passed to my paypal purchase page once the submit button is clicked. Currently when the submit button is clicked it emails the info inserted into form to me via a php script. I still need it to do that, but also redirect the client to my paypal page with the total price passed to paypal.

I know this is a very quick job for those who have the know how; I dont have the know how, so need help asap. If it was a set amount on the form, I could do it easily.

Just adding a few lines of code, so please be reasonable in your bid.