Construction costs are currently skyrocketing

The construction site power box also has a meter number as already mentioned, if you have a meter you can choose the contract ;)

Of course, that requires a willing neighbor

There are no neighbors yet ^^ there are connection pillars on every property... The most expensive option that Bayernwerk naturally offers

Simply sign up with the provider of your choice ;)

My experience shows

The construction site power box also has a meter number as already said, if you have a meter you can choose the contract ;)

Well, that doesn't necessarily have to work. Providers can block that (was the case here). Therefore, we moved the house connection inside as quickly as possible before the house was heated up.
Because if you put aside heating/drying with electricity, not much electricity is used for construction power. It's a few hundred euros for a single-family house. Whether the kWh costs 10 cents more or less doesn't make much difference.

Currently, the district heating is being discussed... I think the biggest consumer will be the crane...

Drying or screed heating using electricity or if a construction trailer is heated with fan heaters over the winter is bad (prohibit!). Otherwise, you will spend 300-400€ for the entire construction phase.