To join a startup, you need to know several things you need to know in addition to the usual job stuff - how much finding does the company have (i.e., how long will it last, who is backing it, etc), will I get equity, and how much (usually in exchange for a lower salary because the funding isn't infinite), and how the team is structured.
Don't join a startup that wants you to earn less than elsewhere if they are looking at getting fun rooms, nice desks, top notch offices, etc. Join a startup that can offer you other benefits that other companies can't - working from home (save on commuting costs and time), better/flexible work hours, and so on.
The startup should offer a sizeable portion of the company as equity amongst the team. I don't know what the going rates are, but if n% of the company was given to the initial team then you would be wanting to look at n/10% for a senior dev, n/30% for a junior dev. This would drop as time passes (hires become less 'foundery' - so don't join a startup that's past the initial equity handouts unless they give even more away (and this is worrying in itself). If it's old enough to get more funding, it's not a startup and you should expect standard job benefits.
And, of course, the whole point of equity is to make a real gesture regarding the company being "your startup", beyond words. The vision is important and needs to be sold, but it means nothing without actions. Sadly I think this guy wants the benefits, and the long hours, and the low wages, without any such actions.