Determine construction power costs / eOn charges too much

how long did that take for you?

Promptly...

Construction started in February, the power connections were laid by July.

What do you think, how much electricity costs a crane etc. consumes?

75 is rather too little. I pay 160, on the one hand we have two construction sites, on the other hand the electricity provider did not know that. If you have to do the functional heating with the construction site device and possibly use a dehumidifier, a lot of electricity will be consumed.

We are currently heating the screed, for example, and after 8 days have already used 1600kwh just for heating. The exact costs afterwards therefore strongly depend on what you do with the [Baustrom].

Must you pay that much?

You don't, it's only 75 euros. Then the final bill is either steep or not.

We have paid a total of €1,200 for construction electricity ([Estrichheizen über Wärmepumpe und zwei Bautrockner]). Now, after moving in, we have about €70 heating costs and €50 household electricity per month.

Do you have to pay that much?

You pay as much as you consume. Strange question.
Calculate about a 1000. Could be more, could be less.