Cash might count as taxable income whereas this might just be part of your student account that there’s a deal on. In other words this isn’t fungible for a cash benefit - it’s either this or nothing not this or $200 in your pocket.

And while agency in finances is important, if this helps you finish your schooling faster, I suspect you might not care how you get access to a frontier AI model and having 10% of a theoretical $1800/mo carved out isn’t a huge deal.