Vacuum Robot Vorwerk Kobold VR200 / VR100

No, that costs 1500 euros WITH vacuum device - read properly. And a company that sells the systems usually does not install them - therefore I rather assume the 4k is for self-installation or plus installation costs.

Says who? The architect??? Then she has no/little idea...

A cheap vacuum cleaner it certainly is not, but 4k is exaggerated. Pure material costs us for three floors plus garage not quite 1300 euros. Just the piping with the suction sockets cost me 220 euros in electrical labor, then I have all options open for later (central unit will only be purchased when the important things are paid for).

You didn’t write about having the vacuum, but that you don’t have the central unit yet... Regarding reading; you write that it sounds like without. Still, that’s a bad comparison, because first of all, no craftsman costs etc., and then it also depends on the number of valves etc., and there are certainly price + quality differences there and with the unit (depending on how much performance or comfort and so on one wants). So better that the architect says 4k than 2.5k and afterwards it gets more expensive because the demands are higher...

Or the manufacturer says more first.

No, not a bad comparison, see my last post regarding the offer from the sales company.

And I’m not saying it sounds like without - just because you understand it that way. I said "pure material [...] is at [...] 1300 euros" and then "Only piping [...] with the suction sockets cost me 220 euros in EL" - what is unclear about that?

And if I had 3 more sockets, it would maybe be 100-150 euros more in material costs. So totally irrelevant...

Of course buffers are good, but the architect advised against them for cost reasons. One manufacturer doesn’t make a buffer either, but as a good manufacturer/sales company, they should give a serious offer according to the specifications.

Read your post, you also wrote that the central unit will only be purchased by you later! And with that it is then misleading that this is included in the costs. That is why I quoted the entire text! And still, you are comparing apples and hazelnuts in terms of price here. With the 4k, it is not about how much the manufacturer would have cost for your service in your house with your devices. However, one can agree that you should definitely obtain several offers.

Oh Saruss, 4k is simply excessive if you’re not planning a palace of 400sqm. And I just assume that... but what experiences do you have with central vacuum systems?