Go south... Or west
I've got 8 acres next to mine I'm buying for $24k.
With a nice creek. No neihbors and secluded. I paid $33k for my 10 acres.
To give you some comparison.
Good advice. Water is essential. Google county tax records for the counties you are interested in and click on an option that gives you all the land sales in the past year, check thier location and view them with google maps-sattelite, and you will get an idea of land prices in that county. Otherwise and maybe in addition look at a lot of land parcels for sale and you will get a feel for land values and prices. A lot of leg work, but it works.