They asked YOU to give THEM money!? That's absurd. I've worked in startups in San Francisco for a few years and have never heard of this. I wouldn't bother.

They asked YOU to give THEM money!? That's absurd. I've worked in startups in San Francisco for a few years and have never heard of this. I wouldn't bother. I'm sure you can find another startup who needs frontend work that wouldn't ask you to pay them.