payment owed is a form of paying which will allow you to bypass the 4% paypal will take if its sent as ''goods''
to do it its dead simple. go to the usual ''send money'' screen. type in the name/email address and the ammount then instead of clicking go to personal
then select ''payment owed''
the trouble with this is that if anything goes wrong, you'll have no comeback - you cant file a paypal dispute so make sure you trust the seller - or add the 4% and pay with the normal channels.
some sellers will let you off the 4% - i wont - as they incorporate that into the pricing.
hope this has helped