Is a minimum purchase custom Payal Buy Now form allowed

Is a minimum purchase custom Payal Buy Now form allowed

I have a PayPal item that allows for a discounted price if a minimum quantity of 25 is purchased. The default PayPal buttons in Zoho do not allow for such an option. I have found custom form examples that allow one to create a form with a minimum purchase quantity and than create and add a PayPal Buy Now upon form submission. I know Zoho Sites does not allow for forms in general, but can this be done for a PayPal specific form. If not this is a much needed feature. A simple search on the Internet indicates that a lot of PayPal business customers want such a feature available in a simple fashion. Zoho could definitely could get new customers with a PayPal widget that offers such a feature.