Sanitary offer - realistic & reasonable?

In the bathroom showroom of a general contractor, there is a rain shower with thermostat four-digit, but often also a house brand for 300-500 €

(especially since similar products can be found on the Internet for about €100-300, without installation,

You have to compare identical and not similar items, absolutely. Installation & installer’s margin included in the price, plus possibly an obligation through a potential general contractor?? Therefore, no information can be given to you here, and the price comparison alone won’t help you. For example, there are quite decent overhead showers for little money that you could easily retrofit later if you install only minimal standard now. We have two different models from Grohe here, but in my opinion the differences are marginal, although the price difference was significant. In any case, I would have the riser pipe for the overhead shower routed inside the wall, i.e., without a rail.

You have to compare identical and not similar, absolutely.

How? Then I would first have to find out the installation share in the offer or have it given to me. Furthermore, there are no prices available on the Internet for the brand, as they only supply to craftsmen (sophisticated system).

In any case, I would have the riser to the overhead shower installed in the wall, that is, without a riser pipe.

The offer/product is intended for surface mounting. Concealed installation would exceed the budget, I was already told during the sample selection...

How so? Then I would first have to find out the installation portion in the offer, or have it given to me. Furthermore, there are no prices available on the Internet for the brand, as they only supply craftsmen (sophisticated system). The offer/product is intended for surface mounting. Flush mounting would exceed the scope, I was already told that during the sample selection...

I don't know your contract and the circumstances, so I don't know. Maybe you have to take it like that and at these prices from the general contractor. To what extent and why flush mounting "exceeds the scope" I would have to be told. Maybe it’s not too much after all and it also depends on how important it is to you. I definitely want it that way and will pay the extra cost but as I said it depends on your circumstances. If it is from Vigour, you would also be in their system and they have all kinds of models, including flush mounting.

For example, there are quite decent overhead showers for little money, which you could also easily retrofit later if you are getting minimal standard installed now.

We installed them last year - here is the result
https://www.hausbau-forum.de/threads/regendusche-nachruesten-tipps-erbeten.32726/page-5
I’d say: it’s not the best of the best, but we had to save back then... maybe at the wrong end?
No, we had bad experiences in hotels back then, and now: a rain shower is not that cool for washing your hair anyway.

I often say....also on this topic.....that many things are overrated. If it fits and I install it myself for a reasonable additional cost then yes, otherwise no, because the added value is marginal. I faced endlessly expensive systems and then we retrofitted the Tempesta model from the hardware store for 160.- and it works perfectly. The other one is 24cm wide....fun but the difference is so-so.......the price difference for me was also only small in this case, since it was only a product surcharge, nothing more.