... 'contract relating directly or indirectly to the purchase of the right to use one or more immovable properties on a timeshare basis`, hereinafter referred to as 'contract`, shall mean any contract or group of contracts concluded for at least three years under which, directly or indirectly, on payment of a certain global price, a real property right or any other right relating to the use of one or more immovable properties for a specified or specifiable period of the year, which may not be less than one week, is established or is the subject of a transfer or an undertaking to transfer ...