You are completely reasonable. I've turned down offers because of this exact reason (and it was the only problem with the offer). I tell them that if they won't

You are completely reasonable. I've turned down offers because of this exact reason (and it was the only problem with the offer). I tell them that if they won't give me the denominator of the equation, I'll assume it's pretty close to infinity, and value the options aspect of the offer at $0. I think it's shady and manipulative to not provide such details ("but we're giving you 50,000 options!"). What are they trying to hide?