here is the bridge: Philips Hue Bridge you are right, that should really be noted.

This has also happened to me with Hue products. It's a real pity that digitec doesn't finally adapt this. By accessories I mean optional components. The bridge is clearly not one of them.

Why is the "Basic+Extension" cheaper than the "Duo" set? Can the "Duo" set do more or is it simply pointlessly overpriced?

This is not digitec's fault but Philips'. Because regardless of WHERE you buy the products, nowhere on the package is it really obvious that an additional product (bridge) is missing. It was the same for me with only one bridge. By the way, you can also connect it to the PC or download an app on the desktop, then the lights are also synchronised with the music or the games. Pretty cool part eigtl. But completely overpriced marketing :-)

However, they do not only work with the Hue Bridge, but also with other Zigbee bridges, e.g. the Raspbee.

So I didn't have to connect the Brige, it worked without it via the Hue app. I bought the Brige extreme, well, I'll try to install it anyway. Let's see what advantages it brings

Google.com is happy to help you find out about Philips Hue and what you need to get it.

It says at the bottom "is an accessory of" or " accessory" ....