One of the most common outputs is relays, thankfully those are pretty cheap. Displays are getting close your price which is great.
Depending on what you're doing you may want to consider purchasing something like a kindle fire for 50$ though and rooting it. Or even a pre-paid "smartphone" for under that much. Then use a microcontroller with it for GPIO.
Depending on what you're doing you may want to consider purchasing something like a kindle fire for 50$ though and rooting it. Or even a pre-paid "smartphone" for under that much. Then use a microcontroller with it for GPIO.
Non-touch 11$ - https://www.amazon.com/MakerFocus-128x128-Picture-Graphic-Ro...
Touch 15$ - https://www.amazon.com/Elegoo-EL-SM-004-Inches-Technical-Ard...