I want to go ahead and buy Turbo Tax before March 16 sales increas. However, I plan to file an extension. Can I buy it now or do I truly have to wait to pay until I file?

To pay the TurboTax online account fees by credit card, click on My Account at the top of the online program screen.  Then click on Print Center.  Then click on Print, save or preview this year's return.  On the next page, to pay by credit card, click Pay Now.  On the next screen just click on the Continue button.  The next screen will ask for all your credit card information so you can pay for the account.