the shopping list
Three things, and two are optional-ish.
Perch was built to give a Pi you already own a second life, so check the drawer first. These are the parts the original runs on. Close equivalents are fine, and the grid is proportional, so other panel sizes work too.
partwhat to look forrough price
Raspberry Pi 5$60–80
A 4 works; a 3 will be slow. 4 GB is plenty, 8 GB if you want the fully local model to breathe. Add a heatsink or the official cooler, because sustained local inference will find 84 °C without one. Not married to a Pi either: any Linux board that drives a screen runs Perch, and the docs carry the short manual path.
$60–807-inch DSI touchscreen~$60
800×480, MIPI DSI, capacitive touch. The common Freenove and Waveshare panels both work. DSI leaves the HDMI ports free and the ribbon keeps the desk tidy.
~$60USB mic + speaker$15–25
Only for the talk button; skip both and everything else still works. Any USB mini mic and any powered USB speaker will do. Perch finds audio devices by name, so cheap is fine.
$15–25SD card + PSU$15–25
You likely have these already. 16 GB and up, and the official 27 W PSU for a Pi 5.
$15–25Some links on this page may become affiliate links through Amazon Associates and similar programs. They cost you nothing and send a small percentage toward keeping Perch maintained. As an Amazon Associate the author earns from qualifying purchases. The parts list itself never changes for money; it is exactly what the original Perch runs on.