If 750€ monthly rate is not affordable with this = normal rent for a 3-room apartment, when then?
how do you come to 750 €?
he will certainly get a poor condition. Combined with a full repayment in the 15-year range, we are at 1,400 per month for 15 years + additional costs which are higher for an existing property.
This means that we have to calculate around 2,000 € / month for interest + repayment + additional costs.
The OP already can’t save now, how should it work afterwards? But yes, he can also repay 2% and then still struggle with a final payment XXX in 15 years.