ariat has the heritage contour boots ($289). then there are the tredstep donatello 1 (bad zippers, but $199, discontinued soon). those are the cheapest i know for leather boots. . .you could get the cheap fake leather equistar boots for like $80 or look at a used tack tack store
I got competition boots on horse.com for about 80$ they are really nice I'd recommend those they hold up to my boy stepped on me and the are still looking good they are about 3yrs old and still look new after a good cleaning they also withstand water don't go in waste deep water with them but if you bathe your horse and they get wet there fine I think those boots are really nice for the price :)
My friend has a pair of Ariat tall boots and hers really hold up through anything I'm pretty sure there not very expensive
treadstep makes a pair of $199 tall boots that are very durable and nice looming
Go to smartpakequine online and look at these: https://www.smartpakequine.com/mobile/pt/14508
But hurry if you want them! They are limited edition, I just bought a pair last week and they came in the mail Wednesday, I've rode in them once but so far they are so great!!