State tax filing

Hi Rachel:

 

I have not done my 2018 taxes.  I understand to use TurboTax that I have to purchase the Intuit software.  IF I can find it elsewhere for less money, in an unopened and sealed package will I be ale to use it even though I didn't buy it online from TT?  Also, is that software capable of doing state taxes regardless of state?  Thank you!   Mike