Hickory: You are missing the point completely: you have ALREADY been had. Are you willing to risk it, and your money, again? Don't be foolish a second time!
AFastSloth: You're indeed right! Thank you for your help, i'll spend £17 on the official while it's on sale. Just one question, if you don't mind me asking, can I transfer my current offline save games to the official when I buy it.
Yes, as already noted, you don't have to do a thing. Your saved games are located in your 'My Documents' folder, and the game will pick them up once installed.