First off, you agreed to the sale when you said 'providing you still pay paypal fees its a deal', at least have the decency to wait for a reply!
Second, don't be such an ignorant twat in your replies
'Not my problem if you can't reply quick enough'.
Perhaps a better reply would have been something like:
'sorry mate, I know I agreed to the sale but somebody offered me confirmed payment before you replied to me.'
See the difference in the replies?? One makes you sound like a right tool and the other, well at least you would still have had my respect!