Bushnell trophy camera for me for the last few years. You order a wire from Hong Kong, buy a 6 volt battery, and 4000 pictures later you charge the battery and repeat the process.
Initial battery cost probably $25 per camera. I have run mine for 2 years on the same 2 batteries per camera. Another $15 per camera for a solar charger and you don't have to change batteries for years. Saves money, time and still get more than adequate pictures.