Caveat: 60p RP2350 microcontroller on a board that sells for $40 and has 8MB of RAM (as opposed to the 520K that the RP2350 comes with). But that is only needed for Photoshop. The 520K is more than enough to emulate the Mac 128K.

These are only $10 and you get a screen https://www.waveshare.com/rp2350-lcd-1.47-a.htm?sku=30557

You can use XIP to run code from Flash, so you can be get away with that in lieu of a decent amount of RAM.

The screens are really fragile, I've stuck my fingernail through three and broke one with an inadvertent tap from a screwdriver.

But they're only $10 and still work as a microcontroller.

I thought the same when I read "This was done (...) on a Raspberry Pi RP2350 chip, (...) for around 60p. Add the various extra parts (...) built today for a few pounds in one-off quantities. Call it the price of coffee and a cake in a European café today." "I opted for the Adafruit Fruit Jam (...)" ($39.95)

Unless you're paying $40 for coffee and cake I'll call bullshit.

How much does the monitor cost?