Are you getting the prices from this [0] page? I think that's the pricing for the old API, because it still hast the standard/premium/enterprise split.

In the past, the Twitter API was separated into three different platforms and experiences: standard (free), premium (self-serve paid), and enterprise (custom paid). As a developer's needs expanded, it required tedious migration to each API. In the future, all developers — from academic researchers to makers to businesses — will have options to get elevated access and grow on the same API. > (https://blog.twitter.com/developer/en_us/topics/tools/2020/i...)

[0] https://developer.twitter.com/en/pricing