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".....buy, download or get a CD from Amazon......"

I want to buy 2018 Premier CD.  Amazon is an authorized reseller of Turbo Tax products.  When I go to Amazon I am referred to their vendors page, with sellers such as mjentertainment, OEM XS INC., Xcess limited etc.  Are these sellers considered authorized b/c they are selling from Amazon?  Is it safe to buy these CD's?  They are very inexpensive, I am assuming because the 2018 main tax season is over.  Amazon is the only reseller listed on PaulaM's June 6, 2019 post (originated by Mayrneh) that still has these CD's available.  I do not want to buy a potentially unsafe CD but I would like to save $100.