Whenever a piece of urban land which is so small and so situated that a major portion thereof cannot be used for any practical purpose within a reasonable time, having been bought merely for speculation, is about to be re-sold, the owner of any adjoining land has a right of pre-emption at a reasonable price. If the re-sale has been perfected, the owner of the adjoining land shall have a right of redemption, also at a reasonable price. When two or more owners of adjoining lands wish to exercise the right of pre-emption or redemption, the owner whose intended use of the land in question appears best justified shall be preferred. (n)