As you say, Academics are pretty used to paying for access to data, services, material, etc., but $42k-per-month for limited access to Twitter sounds more like a "fuck off" price than anything else.

How many researchers can and will pay $42k per month for access? What's the market size here? Is this anything more than a drop in the bucket for Twitter?

There's pretty huge gap between $0 a month and $42,000. Even a year of data would require pretty huge grant.

Well I guarantee you the research project I worked on is now gonna get shut down because of this.

Academic work has costs but nothing like 42k per month, if anything that was the entire budget allocation for one RA's salary for 80% of the year.

The current project I am on now, has only been allocated 250k for multiple people (3 RAs) working on it for the year.

Sorry, no time for goalpost-chasing today.

doesn't have to be free but with every increase there will be less research that can afford to pay for the data and with the proposed pricing of $500.000 for 0.3% of tweets it seems that no-one will be willing to pay the price