Construction costs are currently skyrocketing

Stones are hard when wet and dry. A shovel has to handle both scenarios. The topsoil doesn't suddenly turn into concrete just because a year is a bit drier. ;-) They may have to charge higher prices per cubic meter because the bulk material is now dried out and lighter, and the builder can no longer be charged for the moisture (in the bulk material).

Expressed plastically: gravel wet 1.3t/cbm vs. gravel dry with 1.1t/cbm since billing is usually done by ton.

What can happen, however, is that if you dig deeper, this must be secured/caught because the trench could collapse immediately due to the dryness.

From when can one write PM here?
Neubau2022, are you satisfied with your painter? The figure 9k for 138 sqm floor area is hard to scale, do you perhaps also have the wall/ceiling area at hand and how much g/sqm fleece and wet abrasion class would still be good.

Or alternatively comments on my offer, post further above. ;-)

I can only tell you at the end of August/beginning of September, as they will only start working then. But I think it's very good because the painter: a) invited us to his place and showed us how painter's fleece looks after being painted twice (he had just painted his house shortly before) b) also offers us several options on site and shows how it looks when you simply paint over a Q2 to Q3 wall. c) is always reachable and answers questions immediately.

Here is the offer again: