How much do you think a minimum setup with a few cameras would cost to get running?
Is this a couple hundred dollars potential, or more into the thousand+ range?
There are lot of variables, depending on your power and internet situation.
If all you want is something to watch live, any cheap security camera will do.
If you want to review animal activity, I'd recommend only considering the smart cameras with smart "pet" detection. I've had simpler reolink cameras at my house for years and they're great (for the time I bought them). But simple motion detection is painful to use. Wind, leaves, shadows, etc makes the motion events way too spammy. You must chose between missing the motion events you want to see, and having countless motion events from the wind. The artificial intelligence based person/vehicle/pet detection is a game changer. IMO, without that, its too much work and $ for not much usability. So I'd suggest only considering cameras with reliable pet/animal detection.
If you already have power and internet, many of reolink's nicer (more expensive) cameras have a place for an SD card, so they can run without an NVR (network video recorder). If that works for you, there are nice cameras options available for around $100-$200 each, depending on what you pick. But to make that work, you must have both power and internet already available.
They offer fewer cameras in battery powered with solar panel, and that adds quite a bit to the price (maybe $100 per camera, depending on sales, etc). But then all you need is a wifi network.
So for example, if you live on the property and already have internet access, and you just want cameras on places a few hundred to a thousand yards away, I'd suggest starting with building out the wifi network and once you have that, look at battery/solar cameras. Unless power is available where you want the cameras.
Here's a 180 degree viewing angle dual lens camera with pet detection, wifi connected (you provide the power) on sale for $99.
Here's a pan/tilt/zoom wifi camera with pet detection on sale for $160.
If you can power those cameras and provide wifi, you'll like them. The downside of the 180 degree camera is everything is small (but both are very high resolution: 4k)>