Notice the SD price of $12.99.
Now I went and purchased the first episodes in SD for a $1.99. Take a look at the season price for the SD version.
It is still cheaper to buy a season pass upfront as this season has 9 episodes at $1.99 each would be $17.91. The season pass is just $12.99 for all 9 episodes. For a season that is already out you can easily do the math to figure out of the season pass is a good deal. For seasons with an unknown number of episodes like Sister Wives it could be harder at the start of a season. Take for example TLC 19 Kids and Counting that just started a new season. Is $22.99 a good deal? Without knowing how many shows will be in the season it is impossible to tell.
Amazon has a long history of being fair and honest with its customers. This change dose remove a lot of the transparency from the old system and raises questions about the benefits of season pass. In the past you could buy a season pass for $1.89 a episode and know you would save $0.10 for each episode no matter how many how many they release. Now you are left guessing over what is your best option.
The new system also discourages buying a few episodes to try out the show. I purchased 3 episodes of 19 kids and counting before I purchased the full season for $22.99. Even after paying $5.97 I still had to pay $22.99 for the season pass. Now I wonder if I just double paid for the show a feeling that may make many second guess buying a season pass after they already bought a episode or two.