Update policy

Hi, I'd like to buy Mixvibes Cross DJ (as I don't need timecode support), from what i read I can tell that updates bring quite a lot of changes and additions - which is very good, hence my question, as this isn't covered anywhere in product description - for how long am I allowed to download updates for free? as Cross DJ is at v1.4 at the moment, am I allowed to download every update up to and excluding v2.0? or v1.5 will be the magic barrier? anything else?
cheers
cheers