Select the player you want to purchase. He must be willing to join your club, then submit a bid nearly double the player's value. When the offer is accepted, the "Offer Contract" screen will appear. Offer the contract, and the next day go to "Shortlist" screen. Open the player's details and open the "Offer To Buy" screen. Choose "Stop Negotiations" and the player will be transferred for free.
Play in "Found A New Club" mode with a weak country. When starting the career, buy Shaun Goater for about 20,000. He usually can become the top scorer in the league. To find him, go to the "Transfer List" screen. Click "Player Search", find Bermuda on "Nationality", and select "Search". You should find him there.