Need a WP Paypal Plugin, Any Recommendations?

i am including a payment option for events on a website. where users can buy tickets. so there's a particular functionality i want in it. i want for users to be able to fill a form and enter a quantity of what they want. then when they submit they are redirected to paypal website with the total amount already calculated (qty * base price)

cant seem to find a plugin that does that. does anyone have any recomendations? a free one most likely pls. thanks