Answers 2Add Yours
I think he is saying that friends for a prince are usually in the context of power and money rather than real friendship.
I think he means that friendship that comes with a price you will have but you will never truly own that friendship. You cant buy a friendship and still have a true deep relationship with that person. Just like you cant buy love. so you wont have ownership over that friendship, its not fully yours. Also i think he meant that poeple will become your friend but on the inside they are really not.