I remember that another person did it several months ago, I do not advise the average user to do it because it may malfunction at any moment or may not install the parts of the steel safely.
The costs are not profitable so it is better to purchase them from the website rather than assemble them yourself.
In general, it sounds interesting, if I find time in the coming months, I will prepare one and upload a youtube vlog about it.
Check about costs:
$25.27 CAD for all the components from Digikey minus the screen, you can probably get everything for even cheaper if you go through LCSC but I'm not sure if they sell the microcontroller.
Screen can be stripped from modules on aliexpress, banggood, etc. for a few bucks each, or just the screen can be bought from LCSC for $3.66 CAD
Board cost is something like 2-5 USD for 5 boards from JLCPCB