Does Premier contain state forms?
You are comparing apples to oranges. Costco has the desktop software. You are seeing the online software listed on the TT site.
The Premier CD/Download includes 1 state download at no extra cost. Each additional state will be $39.99. https://turbotax.intuit.com/personal-taxes/cd-download/
The Premier Online will cost $39.99 per state. https://turbotax.intuit.com/personal-taxes/online/