Remember that Life has been around like 5 billion years - a continuous computation running on the most sophisticated computer in existence. I don't think we fully appreciate how special Life is, how special we are. It's likely that some manufacturing techniques will be best done, perhaps only done, by humans on Earth. There are many materials (organic ones) that are more abundant here than elsewhere - and in a more convenient location. The solar system is something like a vast desert; the Earth is like a great city. I would imagine that it will take a long time for space-based manufacturing to eclipse that of Earth, and perhaps it never will, for some things. Then of course there is the inherent interest in biological life - tourism, basically. It's hard to say because we don't really know what's possible out there. But I guarantee some products and services will remain economical to provide only on Earth in the long run. (I mean, if you posit magical nanotech then sure, we can't trade. But I think the future is more limited, and interesting, than that.)

Oh, another thing we can offer is 'reboot services' in the event of intense Solar activity. In return, maybe they can deflect an asteroid or comet for us. I think it will work out!