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 incremental approach is good because you can start without all the e-commerce trouble and build up a credible reputation. It would be very nice to do this type of transaction without paying commission. Keep us posted if anything develops.