Seems like this could be an interesting niche for a fediverse project. The only option that seems to think in that direction that I could find is Epicyon.
Seems like an ideal application of the federated technology. Start small as a neighbourhood sharing/bartering network and over time it can expand easily to cover an entire city or such.
This is lovely! It is a pity that currently we do not have a good way of publishing ontology extensions for ActivityPub in a way that makes them more likely to be broadly adopted (though the Fediverse Enhancement Proposals may be used for this). Would be great if you posted something to SocialHub to tell a bit more about how this is implemented.