There is money in firewood if done correctly. Most wouldbe firewooders simply lose out by handling the stuff to many times.
The best approach is to buy it on the stump from private woodlot owners or government forests, where the trees have been marked for a lowgrade thinning. Expect to pay at least 10$/crd. You need at least a 4wd tractor with loader and 3pt hitch logging winch. Fall the trees one at a time, block the crown, load the pieces in a bucket, spin around and hitch up the body wood log length, skid to landing, dump bucket in truck, block body wood, split with axe and load. Then repeat till truck is full. No piling, no playing around with the wood. Sell to rural homeowners who heat their house predominantly with wood who don't mind buying green. Three full cords can be processed this way in 6-10 hrs., if the timber is reasonably good, ie, 8-16" dbh. You must have a good grasp of the chainsaw, falling, blocking and using a 6# maul and make every second count.
With the way wood prices are going, it may be less labour intensive to sell 10'- 16' firewood logs to customers who want to cut their own, if the trucking distance isn't too far.
Getting your timber this way is a good way to gravitate towards logging if you do a good job in the woods. I already did my 5000 crds by hand this way between 1983 and 1994, so I think I've had my fill, other than for recreational purposes.
John