The TTax license agreement DOES NOT permit you to sell you TTax CD.
Besides, it will not be useable since TTax no longer provides update or state download support
Lot of people are selling on EBAY and there clearly is a market for used TurboTax Programs.
While your answer about the legality of reselling may be correct the fact that people are buying TT online indicates there is a market. Where there is a market means to me there are people that find a use for the used CD's. Some of the people may for example have bought an original CD of their own but may have lost or damaged the CD and need to update their previous returns because of maybe an audit or an amendment.
Without the TTax updates (and state download if needed) the CD is useless. Caveat Emptor.
I have been using TT since 2001. While I would not buy a used TT CD there is obviously people that are buying them on EBAY and that tells me there is a market for them. All the people that are buying the used CD's are not "dummies".
So I pay $40 for a used once CD on Facebook.
. It took 4 tried to download. I started my taxes, got half way through.
Now get an error message "there is access to your account. It seems there is a new security for 2020 taxes.
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March 21 2020 bought a new one online from Best Buy $41.39 delivered.
The used one I bought as far as I can tell has new security measures for 2020 and cannot be used by
more than one person unless you give them your account information which would allow them to see your
taxes.