Kinda odd that in 2018, these types of buttonhole cameras aren't super easy to find. I mean they have them on spy gear websites, and we all have phones, and there was Google Glass, but nothing super cool that's an obvious choice.
The Narrative Clip is similar - the Clip 2 sells for about $200, which isn't too far off from the adjusted price. It's not branded as a spy camera, but looks pretty discreet.
A 640x480 VGA camera for Arduino, where the lens is about 1cm, so it'd fit pretty well, is about $5. Throw in a Nano for the board for another $5, and an SD card module for another $5, and you can probably build your own for about $20 all up.
Prebuilt, I've seen a few wireless "drone" cameras of similar quality for $20, and a few Chinese shops carry cameras like this [0] for $25 or so.
But... If you want better than a crappy VGA, you'll be looking for a while.
