So funny see people talk about how it's a rip off, bliz is greedy....etc... Blizzard are one of the most supportive developer's going.
You are not being locked out of content, it's purely optional. Adding a new character and ensuring balance is maintained reasonably well across the entire game is a huge task, made even more challenging with seasons.
I spend more than £13 on a pack of cigarettes and a lunchtime meal deal.
The game it is today, is very far from the steaming turd it was on release, it's a lot of fun and satisfying to play. I'm pleased they have supported it so well over the years and I'm happy to support them in return.