Actually, the „SuperSparpreis“ is not that „ultra cheap“ - from what I‘ve seen so far, there is (very much like on Lufthansa Group) a flat 20 EUR fare difference (for one-way travel) between „SuperSparpreis“ and „Sparpreis“. The only actual difference between the two fares is the inclusion of a CityTicket and the option to cancel the ticket for a fee for „Sparpreis“. So, if you are unlikely to cancel (everybody else will probably opt for a Flexpreis ticket anyway), it practically never pays off to buy „Sparpreis“ instead of „SuperSparpreis“ - even if you use the CityTicket on both departure and arrival, a one-way walk-up fare for the bus/tram/etc. would have to be at least 10 EUR in order to make the „Sparpreis“ worth it (usually, you will never have to pay more than 3 to 4 EUR for a ticket covering thr entire area of validity of the CityTicket). Hence, you should definitely do the calculations before choosing Sparpreis over SuperSparpreis.