Sign Anyone:
Any player you can bid for you can buy! Just make a bid of 1CHEAT2 and then they reject the bid. Then find the players profile and click improve offer. Offer the player a contract and they will move to your club after their contract expires.

Swap for money:
Start the game with 2 human players pick any team you want for yourself.Than pick Real Madrid. Go to find player club when your are with you team go to real madrid pick ronaldo and then compare with your worst player...than swap the two players do that as many times as you like for every time youll get 10 million dollars if you did that a thousand times put ronaldo back at real and go to manager options for real madrid and quit carreer.