The design has a hidden feature: it is a programmable 24x24 display matrix. So if you do not want the QR clock, there is enough pixel matrix to write your own. Now calculate: Arduino+pcb+9 8x8 matrix > 100$ This is a smart device way beyond the QR clock feature
Bear in mind that the display needs to be actively refreshed by the micro-controller. You may have difficulty doing this efficiently with Arduino unless you are familiar with the hardware timer capabilities of the ATMega328 and are willing to write your own frame buffer.
I have no plans to support the Arduino platform.