Trail Cameras

I've had 3 trail cameras over the years, also called hunting cameras. These have a PIR motion sensor that allows them to take a photograph of any warm-blooded creature that enters the sensor's range.
They have produced some reasonable photographs, but one has stopped sensing animals, so I'm looking for a replacement. I would like this to be higher resolution, at least 12 megapixels, so that the results are useful, not just interesting.
A quick search on Amazon lists a couple of hundred cameras ranging from about £50 to £7,799 (surely they are joking?).
The problem is that most of the cameras are not really 12 megapixels. Most have 5MP sensors and some of the famous names (like Bushnell) have even smaller ones, whilst still describing themselves as 12MP.