Why do you need both? All the Desktop programs have the same forms. You just get more help and guidance in the higher versions.
And 1 Desktop program can do unlimited returns. Buy Deluxe OR Premier here
Oh and you can only install 1 version for each year. All the Desktop programs come with 1 free state program Download which can prepare unlimited state returns (in that state). If you need to file in a different state you can buy that state download.