Liv4Rut
Active Member
I think barb wire is fairly cheap. Quick search online showed approximately 1320ft for 50-60 bucks. Granted you usually run 5 strands so 1320 feet would only get you about 88 yards. Fence posts are 5-8 bucks a pop for steel. Then you have the little wire ties but I know those are fairly cheap. The most expensive part is probably wrapped up in pizza and beer for your buddies for helping out. 
Central Iowa
Life Member
This is a good guide, it is 5 years old but gives a good idea.
http://www.extension.iastate.edu/publications/fm1855.pdf
http://www.extension.iastate.edu/publications/fm1855.pdf
wtj43089
Member
Your gonna need wood posts if your ever going to want to hold anythings. Steel posts are nice but bend easily. We run a wood post for every steal post. You will also need big corner posts which are fairly expensive. If you can Use trees as much as possible you can cut down on a lot of costs, but I would not suggest using trees for the long term they are a huge pain in the ass why you start fixing fence. If at all possible I would stay clear of the trees. We run miles of fence and it seems trees fall on them all the time and it f*cks everything up. And once your fence is up I would suggest cutting all the little trees out of it every few years. Good Luck and have fun fencin is a blast