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.
The shared items section of Epicyon is having more development done on it. Extra ontologies are being added for different types of sharable things, and it’s now possible to federate items between instances using the Data Food Consortium format. Items also have a price field, so if you did want to sell stuff, or just charge for postage, then that would be possible. However, this isn’t intended to replace ebay, and is mostly for small scale private sharing between people who already trust each other. Think mutual aid society, or something like that.
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.