I just wanted to post an update or the "final result" because I often miss this in other threads where many people have participated.
We ultimately decided on the following option:
€219,000 purchase price -> financed 100%
Mixed interest rate 2.6%, €970 installment, full repayment, 30-year term, component 1 drops off after 25 years, afterwards the installment is around €400, after 30 years €0 remaining debt
Prepayments possible anytime, up to 10% annually
€26,000 ancillary purchase costs -> financed with a consumer loan
Interest rate 2.99%, €300 installment, 8-year term
Prepayments possible anytime
The numbers are rounded for simplicity.
Next year a home savings contract matures, the profits of about ~€15,000 we want to use largely for the prepayment of the consumer loan to significantly shorten its term.
We kept our equity because, as mentioned, we want to use it for the renovation, landscaping including fences, the kitchen, as well as our upcoming wedding, and additionally keep a buffer for unplanned costs such as a broken heating system.
For us, this was the best solution and we are very satisfied with it. We are with a local bank and were advised there by my brother-in-law. In my opinion, he is not only very trustworthy but also in our age group and therefore will be available as a contact person for a long time if he should have given us bad advice — just kidding, there is absolutely no reason for such speculation.
The total costs, despite the 2.99% consumer loan, are significantly (!) lower than those of the much-praised providers like Interhyp and Dr. Klein. The cheapest offer from Dr. Klein was €30,000 more expensive.