I had a similar (ridiculous) conversation with a startup that had already listed on the public stock exchange.

Okay, if the shares are really worth much more than their current market value, and you want to hire me for $X salary and $X/50 market value worth of your stock, it'd make more sense for me to take a different job that just pays $2X salary in cash, and then buy stock on the market...

I joined my current employer a couple days pre-IPO, was given stock options and told they might be worth a lot. Despite my insistence, I wasn't told the exercise price, nor how many shares were outstanding, nor any other relevant information, so (sensibly?) valued the options at around zero. They turned out to be worth more than my base salary.

Good for you but this is still extremely shady. Any respectable company should tell you how much you are getting and how those are currently being valued. Attaching no value to a private company RSU is pretty smart though.