Trailcampro looks at the electrical draw of images and videos, and can produce an average battery lifespan for each camera based on a standardized image recording rate.
You wouldn't believe how long these new cameras will last on 6 lithium AAs. Some of the newer cameras will literally last years on a set of batteries.
Along with what BSK has said,
there is much more to the cam "cost" than just what you pay up front. There is the
ONGOING "cost for usage", as well as the consideration of what you're getting relative to what you're paying (both up front as well as ongoing).
For example, one manufacturer sells a cam for $100 while another sells a somewhat comparable cam for $200. But that $200 only requires 8 batteries instead of 12 batteries, and those 8 batteries last twice as long as the 12 in the up-front "cheaper" cam.
But where cams can really cost you the most money is in their needing "servicing" more often, as in the fact you must spend gas money and valuable time in tending to them. Worse, when they're less reliable, you may be doing much of that tending work for nothing or very little, such as when the cams are not working properly if at all.
In the case of the particular $200 vs $100 cam above, I figure the $200 cam saves me more than $100 inside only 12 months of usage, plus it's more reliable and has more features.
Lastly, it's hard to figure the cost of a cam that's just not working or not working as well as one more reliable. What is the cost of missing some valuable pics?
But honestly, I take the exact opposite angle that you do. Getting crisp, clear images at distance, so I can identify each buck in each picture/video, is critical hence worth the extra price. I've looked at tens of thousands of images from cheaper cameras and they always leave me frustrated at the poor image/video quality.
