It depends on the land. The cheapest out there that I have seen always has a catch. I found some that are part of a water processing system in which gray water is used to create a wetland, which eventually cleans the water naturally. It takes several decades of monitoring to ensure things don't go horribly bad at first, and a few more to make sure it remains stable. If you see "tank" land anywhere near the water table or downhill, beware, as they may have turned a wash into a creek for gray water. A couple other places I found were near other sorts of less than desirable land uses and one area was super cheap because of a large outdoor shooting range. Often enough, it's just really cheap because it's in the middle of nowhere without road or utility access, little to no timber or water, and lots of rocky soil. Sometimes you will find ranchers parceling out some of their land for cheap, which can be good or bad for you, depending on what you want to do with it.
TLDR: always find out what is going on in the land around the for sale land