n. So 450k€ - 480k€ with a monthly payment around 1700€. That would definitely be a payment where both of us could sleep peacefully. !
1.5 years ago, we built with a general contractor for 430k€ all in at a similar land price. 160 sqm KFW55 single-story city villa, Schüller kitchen with Berbel hood, not the cheapest of everything. It really depends on where you build; in BW or BY the numbers would probably look different. You have to find out how it is for you now. I would also take the chance now; if you feel comfortable there, in my opinion, 50€ more or less per month easily compensates for it, they also hurt less and less year by year.
Take your time to plan properly, but not too much, the schedules are full, more than 1 year lead time is rather the rule than the exception here, and after the construction period expires, the house often has to be finished. That often also takes a good 2 months from construction start.
We also built before our first child. I would always do it that way again. Personally, I wouldn’t "waste" parental leave on the construction site; that month was just too great to get to know each other.