The Wyze Cam Pan indoor security camera costs $30. It's only available in the US, but converts to roughly £25 and AU$40 at the current exchange rate.
It has a 120-degree fixed angle and a 360-degree panning angle, as well as a 93-degree vertical tilting angle.
The camera works with Amazon smart speakers, so you can say, "Alexa, show me my camera" and its live feed will appear on your Echo Show or Echo Spot (after you enable the Wyze skill in the Alexa app).
The Wyze Cam Pan sends motion and sound alerts. It's also equipped to send custom sound alerts when it thinks it hears a smoke and/or carbon monoxide detector.
This indoor camera comes with a power adapter; it doesn't run on batteries.