I think it depends on the player who you buy as I think players generally cost between 6 and 8 tokens to make an offer. This all goes to T11 then you increase your offer to include tokens and then they are split 50/50 so for example your friend needs 10 tokens. Then 10 tokens will go to your friend, 10 to T11 plus possibly 8 more to make the offer. So it would cost 28 tokens plus the transfer fee as well.

Hope this helps.