Instead they massively low-balled me with a lower base than what I was making at the time plus ~30% of the RSUs that they'd need to hit my number. I asked the recruiter and the company both about this and they said that the value of the RSUs was predicated on "their growth potential" and that I had to account for their future value. I double-checked with the recruiter to make sure that there wasn't a miscommunication and they confirmed that the company knew what my requirement was.
Needless to say this made my decision fairly simple. Their share price was in the toilet and I'd never worked for a company that granted RSUs before so maybe they thought that they'd be able to pull a fast one on me, but it was a colossal waste of everybody's time regardless.