Electrical installation without sub-distribution

Hello! After having dealt a bit with the topic KNX, I am increasingly coming to the idea that a conventional installation, as described at the beginning, could be significantly cheaper for me. As mentioned, it is a very simple floor plan and if I bundle ALL the cables in the utility room without sub-distributions, I am also relatively flexible. I can also cobble together the smart functionalities with Alexa and Co... I just fear that I really need to make a plan and compare the costs very precisely.....

if someone could please tell me an online shop where one can buy KNX hardware...

Voltus specializes in KNX and smart home in general and has a very large range at mostly affordable prices.

I still don’t quite understand your conclusion. What use are all the cables in the utility room without control/bus cables? If you want to rely on wireless, then you can also save most of the cables in the utility room. To control and switch, you need actuators, whether there is a KNX or "Alexa" sticker on them (figuratively speaking) doesn’t make a difference in price. I am still missing the plan behind it; without it, you can neither say anything about the type of installation nor about the (additional) costs.

If the utility room is to be in the middle of the house, the supply connections should also be placed there.