Declined increase in Droplet limit -- how long a billing history is needed?

I am teaching a university course on software engineering with 170 computer science students. We want the students to use proper cloud hosting for their final projects, so we wanted to offer them access to a Digital Ocean Droplet per team (25 - 40-ish teams).

The guide for requesting an increase in Droplets make the process seem straightforward and easy, but my request to move from 10 Droplets to 25 or above was decline due to a short billing history. Since I have a bunch of students waiting I want to know if there is another way to increase the Droplet limit, e.g. paying in advance, adding additional payment options etc.?

(I have a 5 year billing history with Digital Ocean on my personal account)

I totally get the need to impose limits on new accounts, but new accounts might also want to scale from the get go. I feel like it would be good opportunity for my students to try Digital Ocean early in their Computer Science degree. It would be disappointing if we had to move somewhere else.

So, what are my options?

Best, Henrik, Denmark