(Assuming your in the USA) Check around your comfortable travel range for military posts or National Guard armories. Then look for pawn shops. Probably decent prices but selection (condition, sizes) will be all over the place. And as has been suggested elsewhere, military surplus, especially if they are located near some military post or base should have a pretty good selection and manageable prices.

Its getting harder and harder to find them, but if there is a boot/shoe repair place locally they might be able to give recommendations as well as be able to give you an idea of what kind of repairs they can do. Resoling probably won't be that big of a deal for general walking. (The only two times I destroyed the soles of my boots were from grinding dry sweep into oils spills and the military issued desert boots soles just melting off from the heat ... which... what the fuck.) If they can restitch the leather panels would be amazing because my attempts to sew panels back together always results in failure.

If you get something online, in my recent experiences, price does seem to matter. I was (and am still) looking for decent quality but affordable recruit/jungle boots for wearing around the farm. I found some 25$ jungle boots on Amazon (the company/brand , the leather was super stiff and no amount of leather conditioner and light use seemed to soften them up and after 3 weeks serious cracks started forming that went completely through. A second pair of boots from Amazon, Ad Tec, were on sale for like 80$ and had soft leather that hasn't cracked apart but the stitching started to fail on one of the boots after the return period. The heel of the style that I have is higher than the toe which seems to make them wildly uncomfortable for walking on uneven terrain and they're heavy as fuck.

NOTE 1: Get some leather conditioner stuff like saddle soap and water proofing like mink oil (pretty sure it isn't actually made from mink). Probably works decently on vegan boots but you might want to do some quick reading to make sure there isn't a specific product for vegan boots that would do a better job. Get in the habit of at least wiping down your boots a few times a month and applying the saddle soap/leather conditioner of your choice. More often if they get really dirty (lots of mud, sand, oil, fuel). Dirt in the stitching can slowly cut through the threads of the stitching.

NOTE 2: Don't be afraid of returning the boots if anything feels off or wrong. The Ad Tec boots that I mentioned, the boot that's actively falling apart had some piece inside that I could feel on my heel (pretty much where the stitching started to fail between the leather panels) that felt a bit weird and I've been wondering if that was a sign of that particular boot just having some kind of manufacturing goof-up that should have been a warning that something was wrong.