Yes, OpenBazaar is very similar and had a great success in this field.
But the main idea of OpenBazaar theory is decentralization, and the main idea of this system is implementation bitcoin in real life.
Some difference between these two point of view.
are you more thinking of an open bazaar which advertises products
or more so a "spend bitcoins" where to go signposting site(map)
maybe another idea. is a mix of spendbitcoins/local meetup signposting(map) site.
that shows where the regular meetups/garage sales occur..
i dont know exactly what your site will offer. as i feel your still at a first draft, initial thought position