Yeah but what's the difference from buying a player from a stranger or your brother or your uncle? You're still buying a player..there's no difference at all. Seems pretty stupid :/
but if the deal is considered a bit to high, then you could say a stranger was a bit stupid with the bid but if this bid come from someone you know you could also come to the conclusion that this is cheating(and you don't need to make extreme bids for giving a transfer a bad taste)