Updating Navi software

Two years ago I had been able to book a total of 8 quarterly updates for my Navigon for only € 20. These have now come to an end and in order to continue to receive them, € 90 would now be due. Is this worthwhile for a device price of around € 150? Or just look for a new Navi with a favorable update offer – you would have with it again 2 years warranty in the bag.