A few years ago, I built a simpler version of that device myself.

As you said: A 90% solution is easy to hack together. I had mine displaying Skype for Business status so my colleagues would know if I was in a call or just listening to music.

The harder part or much rather the time consuming part is getting a good status message from the installed apps. It looks like there is plenty of software and APIs available.

The Ulanzi TC001 devices are kind of near (without the double screen and all the buttons and stuff) for around $50. IIRC they have an ESP32 and have at least 1 or 2 alternative opensource firmwares.

or maybe a repurposed eWaste phone/tablet, or at this price probably a new phone.

Can confirm, here’s a small BOM:

8x 8x8 WS2812 Matrix $2 each = $16

ESP32 $3

1x some acrylic to laser-cut a case in a makerspace $5

So $24 total. The screen would be much larger than the Busy Bar version, which could be a pro or a con, depending on what you want.

If you need the smaller back screen (I don’t see the use because I would control it from a computer anyways), that would add another $3 or so. The buttons are basically free but if we assume $3, that’s $30 like you said in total.

no, that's not how much that costs at all lol

Ever been on Aliexpress? I was roughly converting prices from € to $ and adding some spare for tolerance, here’s what I actually paid:

LED Matrix: 5 for 6,33€ (that is 1,27€ each)

ESP32 C3 Supermini: 3 for 3,56€ (1,19€ each)

There’s scrap acrylic at my makerspace so I was guessing, make it 10€ and I’m at 23€ or so.

What numbers do you not believe?

Who’s doing the case? Who’s doing the buttons? Who’s gonna put it together? Testing? Programming? Flashing? How about handling returns? Packaging? Design for all of the above?

Well that’s the point of a DIY project, you are going to do it (if that’s the kind of project you want). I wasn’t saying you should build this thing yourself because the busy bar is bad, I was just giving some more data to the original commenter who said you can build something similar yourself for much cheaper.