There are several companies that create portable saw mills. It appears that the mills have the ability to create a variety of commercial grade lumber products.
You mentioned that the wood from the lumber yards have been going up in price. I think it would be possible for individuals and small groups to create a profitable business turning local wood into lumber. There are still a few people in this world willing to pay a premium for local products.
Wood Mizer has been making portable mills since 1982.
Woodland Mills has a lower cost mill.