We don’t do that. We took our time searching and bought a house last year with a slightly higher income and one child – but not with such a loan installment. We don’t want to make the dream of owning a house possible at the expense of a relaxed life. We both experienced that with our parents. We also had to finance almost the entire studies ourselves because as children of teachers, there was no Bafög. I don’t want to put my child through that to that extent.
Of course, everything always has to be considered individually and always depends on the attitudes/values the parents convey to the child.
I myself am not yet a parent, but I see different "parenting styles" in my close environment – but here you can also clearly see financial differences. "Normal" people – however, some parents repeatedly buy their 2-year-old child new nice Nike shoes, lots of toys nobody needs, etc. The other parents invest in the stock market during the first years and are satisfied with fewer toys for their children... Of course, this can also mean that one couple can pay off a loan of 500€ more/less. This should always be taken into account and applied individually to one’s own "method."
That’s why it’s always hard to say whether the loan is too high or too low. However, the original poster gave a cost breakdown. Ultimately, forcing the original poster to use a different cost breakdown just because maybe "statistically" or personally different amounts are spent on certain things is simply wrong.
Edit: What I want to say is that the original poster knows best how much money he currently needs, since one child is already born. I assume he’s smart enough to also add those costs for the second child and knows what a 16-year-old teenager, for example, costs. However, all that is also future talk, which in my opinion doesn’t always have to be fully considered. In 10-15 years, the wife will work again, then the financial questions one asks oneself are almost over anyway.
My personal opinion remains: I would not invest that much money in the original poster’s current life phase.