If you saw a website offering any edition of TurboTax for $9.99 it is not an authorized TurboTax re-seller, probably pirated software and more than likely has viruses and malware included in any software they sell.
This is the official website for TurboTax - https://turbotax.intuit.com/
The TurboTax online editions for 2018 - https://turbotax.intuit.com/personal-taxes/online/
The TurboTax desktop CD/Download edition for 2018 - https://turbotax.intuit.com/personal-taxes/cd-download/
