The USDA puts out a great fat thing called The Wood Handbook. It contains an astonishing amount of information about the mechanical properties of wood, including a chart by species that expresses shrinking as a percentage of size. You could look it up.

Dry wood almost always costs more than wet wood, and is usually more difficult to work. Someone had to own the stuff and hang onto for a while for it to dry naturally, your low-tech option, or someone else had to buy one of those great whacking whiz-bang kilns, pour megawatts of electricity through it and ship the resulting 'product' around the world.

More than a few quite servicable and lovely timber frames have been assembled from green or air-dried wood over the last thousand years or so.