If you have purchased the CD/download for TurboTax, it was paid for prior to the actual download. There isn't an additional fee to download the program. There are no additional fees to complete and file your federal tax return. The only additional fees that you may have with your purchased download would be if you added another state program and paid the state e-file fee or have chosen to add-on features like audit defense.
Click here for TurboTax Desktop pricing.