Here is how to tell if your split log is seasoned. Drop it from waist height onto concrete. If it rings with a hollow sound on landing, it is good to go. If it hits with a solid thud, it is not ready.
I use this little trick all the time, since ANY wood here is called seasoned. If they cut it from a dead tree, and it is fresh-cut, that is "seasoned." Uh, no it is not!
Species of hickory, including pecan:
http://www.cas.vanderbilt.edu/bioimages/pages/compare-hickories.htm
People argue here and say "That ain't hickory" if it is not shagbark. Oh yeah, it is. Know your wood.
As far as quantities, wood here is sold by the "rick." The current price of a rick of split seasoned wood is $50-$100 here. In many cases, if you say you are using it to smoke meat around here, it will go more toward the $100 end than the $50 end, so all my wood is bought to heat my house.
It takes 3 ricks of 16" long wood to make an exact cord. A rick is 4 feet by 8 feet stacked, and is customarily 16" long, but there is no hard rule on length for ricks, so if you get short-cut wood and buy 3 ricks, you are short a full cord.
A cord of wood is 4x4x8 stacked, period. If you have your 3 ricks and they are 16" long, you can multiply the per-rick price to get a cord price. This makes it easy to compare prices. On the other hand, if a seller seems cheap on price but his wood is shorter than 16" you know he is shorting you a full cord at 3 ricks. If you will measure your arm to see where 16" falls on it, you can casually and easily assess wood length at the cutter without the need to pull out a tape measure and maybe offend the cutter.
Know your measurements and what quantity and stage of seasoning you are really buying. Every cutter has his ways. You want well-seasoned wood, but not wood older than 1 year in the woodpile for best results smoking meats.
You are correct, it is significantly cheaper to use wood bought by the rick or cord. Here's 2 1/2 cords of hickory, with a smidge of maple in front...