Costs numbering property developer/self-purchase/goods/assembly - ok?

Even though the last post was already a few weeks ago, I would still like to briefly comment on the price difference.

For us, it is about a main bathroom as well as a guest bathroom in a new build apartment. The standard is a joke, and the surcharges for our desired products from the new build plumber are outrageous... he wants EUR 17,000 (the installation etc. is, mind you, already included in the purchase price of the apartment - the higher effort for the larger washbasin, for example, will not cost thousands of euros), another plumber does the same for EUR 12,000, including installation. If I buy the items (even the accessories etc.) myself, I end up at EUR 9,000... for EUR 3,000 I can find enough craftsmen to install a few bathroom furniture pieces for me.

And now I ask myself
a) EUR 5,000 surcharge at the plumber commissioned by the project company... for what?
b) what do I have in case of warranty? Will the plumber take the blame? Hardly! I claim that in case of emergency, the nasty finger-pointing will start!

If I commission the new build plumber, I could blame everything on the project company if something goes wrong... however, they will blame the plumber, and he will blame material weakness or something else.

So why not buy everything myself and commission someone? After all, we are talking about at least EUR 5,000 savings!

I will give the plumber commissioned by the project company a chance and politely but firmly tell him that he should please reconsider his offer... if that doesn’t work either, it’s out for me - but that certainly won’t bother him, as the project company is currently building a total of 160 apartments in the district, and he has been commissioned for the installation everywhere.

You must always keep in mind that with 160 apartments you have zero negotiating power... Whether you feel more comfortable with an external plumber in the next 5 years is a decision you have to make.

We already know which bathroom furniture we want - whether the project plumber installs it or a plumber commissioned by us makes no difference. The desired products should be installed and commissioned, and ideally I won’t have anything to do with the plumber for years.

Spoke with the paramedic yesterday - "I don't make any money on it and only add 30% because of the warranty"...

Much respect... "only 30%"... my definition of "not making any money" differs quite significantly from that of the [Sanitär-Betrieb].