My current pay is probably 10-15% above average. Funding is more to the 2-4 range. My main concern is whether the equity is within the "average" for first developer on deck in a startup with VC money
Walking away from lowball offers makes you worth more in the long run.
But I'm assuming you're a developer and the founders aren't and if they are trying to hire you, you have a certain set of skills they want.