This addon allows Shopowner to offer a Payment Method "Request Paypal Invoice".
This module asks the Customer for their Paypal Address so that shopowner can then send a Paypal invoice to the customer. The Customers Paypal Address shows in the Order Summary infobox and on the Invoice.
More or less, this module allows the customer to not pay until shopowner sends an invoice. After payment is received shopowner can then update the order as normal and send out the goods.
This addon changes ZERO core code - simply upload and it is useable.
Please note that this Addon does NOT send a Paypal Invoice automatically. Shopowner would need to log into Paypal and do this manually.
If the price of this addon does not suit your business, contact me anyway. I'm sure we can come up with a good deal that suits each other. Prices are not set in stone.