What?
The tax records itself cannot be sold to anyone. Like I said, it's a felony for anyone to view them without authorization, let alone selling it.
What you may be thinking of is the information including your names, e-mail address, home address, age, etc. Some companies will sell these sort of information to a third party, but they cannot sell tax information or any information that may present a security risk to you. For instance, your social security information, driver's license, all sorts of information that can be used to commit identity theft.