How many inspections by a building expert are appropriate?

What do you think, how many inspections by a building surveyor are appropriate? We are builders and have an offer from TÜV Süd with 4 inspections, see picture below. Is 3 + 1 too few?

The question is whether it has to be an expert. There are civil engineers who offer construction supervision and charge based on effort. The costs are definitely worth it. I am usually on the construction sites about once a week, in addition to events such as the installation of concrete stairs, precast ceilings, before screed, roof truss.

What do you think, how many inspections by a building expert are appropriate?

Not only is your name "HeiniohnePlan," but you also live up to that name: we still don't see any plan of your house here. Therefore, it is not possible to make a qualified guess about how many or even where specific critical points are. Whether you place a Flair 113 on a slab foundation lot or a Falling Water House in a vineyard makes a considerable difference. Also, whether your house stands alone or is a semi-detached and your neighbor builds theirs differently.

We are building a solid single-family house with a general contractor on a flat plot with existing buildings.

Not attached to the existing building, but without a supervising independent architect?

Thank you for your feedback. The existing building will be demolished and we have a construction supervisor architect and a general contractor.