This is an interesting conversation for someone looking for rural land. Here is something I'd like to point out: it depends where you want to buy and who is helping you, professionally. When I lived in the midwest, as you drove down the highway, you saw county roads on a one mile apart grid. the exception was land features like a lake or river, a railroad track, an interstate, etc. It's gonna be kind of unusual to get land locked inside of a 640 acre square surrounded by corn or soybeans.
In other areas such as the plains, foothills and mountainous ranges, things are completely different because the land use is different. If I was looking at a parcel in a far rural area I sure the heck wouldn't want to deal with a realtor who didn't understand the area. When I bought the land we have now the realtor we contacted should've known the simplest of details - like how to get here but she was just lazy and I doubt she had even seen the properties. We contacted someone else and that gal met us at a nearby land mark, led us to a given place and had her GPS and survey pins and L/L. She scrambled up a 60% boulder strewn grade stopping for us (mainly me) to catch up and on top opened into a plateau from where we could see Mt. Adams, Mt. Hood and Mt St. Helens (obviously a good sales person). She walked us straight to a survey pin with her GPS. The story goes on from there. But my point is that this realtor knew and gave us details that we didn't even know to ask - like the easements on the private trail that went through 3/4 of a dozen 40/80 acre parcels to get here. Guess who represented us as buyers?
Upon us making agreement that she would represent us she reviewed and provided an abbreviated abstract and the latest survey. In her investigation she found out that two adjacent parcels had been listed but were not in the MLS system yet (the non-resident owners didn't know each other were selling). She advised us for an initial bids on each. All three parcels closed at the same time before anyone knew what was going on.
At some point, and especially if its for sale by owner, your gonna have to get professionals involved. Choose wisely.