US$50 in small qty, bulk discounts. Propeller 8 core microcontroller, LiPo charger, 128x64 OLED, buttons, proto area, AV IR USB etc.
"There’s plenty of hardware on the badge, including a high-brightness
0.96” LED display for text or graphics, infrared transmission/receiver,
touch-buttons, blue and RGB LEDs, accelerometer, and A/V jack. The power
supply is a rechargeable Lithium Ion battery with 12-16 hours of run
time and USB recharging. The prototyping area is used to add your own
twist."
https://www.parallax.com/downloads/hackable-electronic-badgeFull specs on the sale page
https://www.parallax.com/product/20000