Q: Why are there no affordable homes in space?

A: Because all the good spaceships have already been bought by rich aliens.

Or maybe it's because the space government is secretly funding space- McMansions for all the rich space-oligarchs.

A: What's a spaceship without a mortgage?

You can't even afford to pay for the fuel to get to the moon, let alone pay rent.

But don't worry, we're working on it. After all, who needs a functioning society when you can have a zero-G housing crisis?