OP, I see that you're in Missouri, but what you described with looking out across fields makes me think there might be some overlap between what you want to do and what we do out west with Elk, Antelope, and Mule Deer. With muleys especially, a lot of us have found great success with tripod-mounted high-power binos in the 15x to 18x range, and if you're doing rifle hunting and porch glassing, that might be an option to consider.
A typical setup out here would be 8s or 10s on the chest, and a spotting scope, with increasing numbers of guys packing 15s/18s. Using the 8s/10s when moving into a spot, esp for initial glassing or moving in on a stalk, but glassing for hours at a time from tripod with the 15s and/or the spotter, and shooting from tripod. Can't speak to what it would be like for you in your geography, but when I've tried 12s, they've been too high-powered for hand-held glassing, but not quite enough power for tripod glassing. They might be fine for you though, depending on distances you have available. People have mentioned Meoptas for your price range, and I'd also give Mavens a look.