It'll be much more difficult to convince citizens to set up a Mars colony at a cost of $1,000,000 per citizen as opposed to only $1,000 per citizen. Therefore,

It'll be much more difficult to convince citizens to set up a Mars colony at a cost of $1,000,000 per citizen as opposed to only $1,000 per citizen. Therefore, I'd argue it is relevant. If you were talking about setting up a privately owned colony - a larger economy means there is more chance of a company large enough to take on this task. (In large economies capital is more concentrated, at least that's what I'm observing from history. It would be difficult to have a company the size of Apple in an impoverished country whose GDP per year is less than Apple's quarterly income, for example.)