Practically anyone in America these days will suggest Wyze Cam, as they are an amazing success story with a high quality, always improving product at $25 and $37, including lifetime basic cloud access and an sdcard slot for continuous recording.
It may be worth trying to import them. Most folks say that they beat cameras which cost 4x as much.
But for “small and simple”, practically any decently rated camera on Amazon or your favorite gadget retailer will work fine. Most are built from the same components - even their “custom” firmware libraries and Apps.
If you have complex needs like multiple-cameras, motion detection, network video recording (NVR), transcoding for embedding in ActionTiles, or SmartThings compatibility, then your search becomes more complicated.