It depends on whether you need a state return or not.
The desktop Basic Edition has all the usual forms, but does not include a state program. Adding a state program to it later would be expensive (approx. $40). But if you do not need a state return, you can find the 2015 Basic Edition at Amazon as a download, and if you order the CD there, it's quite discounted.
If you do need a state return, however, then the cheapest route would be 2015 Deluxe. But be aware that when purchased elsewhere, the Deluxe comes in 2 versions--one that is Federal and State combo, and one that is Federal-only, so you have to be careful.
The Basic Edition also cannot import from ItsDeductible, if that's a concern.