Take the case of Denis Boyce, a Fishtown art gallery owner who bought a lot down the street for $1 in 2002. It came with a requirement that it be developed into a community garden and be kept that way — or as open space — for 30 years. Two years later, Boyce got a certificate from the city that he’d done all that was required. But then in 2016, he sold the property to a developer for $339,900. He didn’t reply to a request for comment.