For comparison, when me and my wife were buying our apartment, we delivered slightly above 20% of the purchase price in cash, not touching 2/3 etc. Our NW (with 2/3 pillars) was way above 55% of the purchase price (I don’t have all numbers for my wifes’ accounts). Now the value of our 2nd and 3rd pillars only is slightly above our debt, so theoretically we can repay it any moment.
We were lucky and were able to buy an apartment at a price way below the market price, though.