At the moment, there's no official confirmation about a season 3. But you never know - if there's enough demand and the right circumstances, it could happen.
The length of Minecraft Story Mode Season 2 can vary. On average, it might take around 8 to 10 hours to complete the main story, but if you explore everything thoroughly, it could be longer.
To buy Minecraft Story Mode Season 2, you could look on gaming platforms such as the PlayStation Store if you're a PlayStation user. Or if you have an Xbox, the Xbox Store might have it. Also, keep an eye out for any special promotions or discounts.
Minecraft Story Mode Season 2's price fluctuates. Sometimes you can find it for as low as $12, but typically it's around $18. Keep an eye out for discounts on different gaming stores.
The Minecraft Story Mode: The Complete Adventure doesn't have Season 2 in it. Usually, when they label it as 'complete adventure', it means it includes all the main content up to a certain point, and in this case, Season 2 isn't part of that.