You'll often find the TurboTax software (CD/download) editions at cheaper rates than on the TT website. That's because the "big box" stores discount the prices significantly to get you through the door in the hopes that you'll purchase other items.
Here's a list of places you can purchase TT software:
https://ttlc.intuit.com/replies/3301381
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
