What only strikes me is that the extra effort for the large format is charged twice. Fine filling is charged for >60cm edge length and still an additional surcharge for the 45x90 format.
... maybe because the price is considered normal by many homeowners and you don't have to deal with fully booked craftsmen in your region?
Tell me, do you even believe your own answer? Where are there not fully booked craftsmen? We live in a structurally strong region where everyone is currently building. And I thought my price was high, so I looked for alternatives. @TE Find at least 2 more offers.
In case it helps you: with us 47€/m², ancillary work 10-30% cheaper than your offer. We consciously chose the craftsman who made the best impression, regardless of the price. For your large area, I would get more offers. We had two significantly cheaper offers (50%) available. The quality of the offers and also the approach to them was very questionable, and we feared that there would only be trouble later.