But if you are hacker and don't care too much about the aesthetics you could probably get 90% of the functionality with an ESP32, a GPIO extender, an LED array, an OLED display and a 3D printed case for like $30.
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.
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?