Ask HN: What counter-offer should I make for the position of CTO at a startup?

[Encryptor]

Dear HN,

One of my friends offered me the position of the CTO at his small self-funded startup company in the real estate market. The offer revolves around the idea of building the company's website, which would handle listings, financial transactions, apartment bookings, etc. It's of decent complexity (we have to yet figure out all the functional requirements). I cannot commit full time and I am also in a different timezone, so I would be working part-time, remotely. The offer includes small cash upfront and 10% of site revenue. Do you think this is reasonable? What do you think my counter-offer for the position of the CTO should be? Alternatively, do you think it's best for me if I suggest a contractor/consultant relationship instead? What other options do I have?

Thank you in advance!