Construction costs are currently skyrocketing

Well, you could definitely say wear and tear on my end. My nerves are damaged. That can be measured. But yes, it's not like that for everyone.

I currently find few offers across the federal territory that are below 1500 / kwp.

We had 1500 all in - panels and inverters from German production

Wear and tear is likely to be significantly higher for an amateur than for a professional. Insufficiently developed muscles are one thing. The other is thriftiness. Where the professional moves the gravel around with the mini wheel loader, the amateur shovels it into the wheelbarrow. It's much cheaper than renting the wheel loader for a week ;)

That's nonsense. If you shovel gravel for 2 or 3 weeks, nothing wears out at all. If that were the case, the professional wouldn't be able to move after 3 years.

Wear and tear sets in after decades. You don't get tennis elbow just because you work 10 hours on the computer for 2 weeks or play tennis 3 times.

Doing it ourselves is not an option for us... We have unsuccessfully tried that over the past years due to lack of money. Now I have inherited, and we can finally afford to have certain things done. We have been living on a permanent construction site for years, and the new house should finally just be a nice home for us and the children. We think it's worth it, but we still do not want to and cannot pay excessive prices...

As I said, only take offers seriously if someone has visited the construction site at your place and preferably also taken measurements. Otherwise, additional efforts may come your way. And have the paving work offered with a gravel bed.

Currently, when I walk through the transitional house, I often see trades I did myself. Or my husband. But I can’t exactly say that fills me with joy. :D One must not forget that with financial savings, one potentially also sacrifices quality compared to hiring a professional. At least if one has about as much craftsmanship skill as my husband and I. And it's not for lack of trying.