Every tax year requires a new product.   For instance, the 2017 product can only prepare a 2017 return.  The 2018 product can only prepare a 2018 return.

   There is no fee for same-year updates/product revisions to that year's program.

The cost of a tax product each year depends on the price in effect at the time.   For 2018, the prices are currently discounted in early filing season, but can rise at any time.   Price increases normally take place around mid-March, but  is not predictable.