Right now is a great time to set up a BW darkroom if you are into doing it yourself. Digital has convinced everyone with a darkroom setup stashed in the closet/basement/attic to get rid of it.
EBAY is flooded with stuff. Enlargers that went for $1000 in 1995 are lucky if they can pull $200. You can find huge boxes of darkroom stuff at garage sales for a few bucks. People will give it to you just to get it out of their house; they need the space.
I have two enlargers, and all the neccessary equipment to process and print 16mm, 35mm, 120, 220,and 4x5 film. I can print, drymount, and mat up to 16"x20". Not counting film, chemicals, and paper, I have only spent about $500 or $600 on my darkroom over the last few years. The stuff is laying around everywhere just begging for a good home.
If you are only keeping track of supply costs, then there is no doubt that it is cheaper to process and print your own BW film; maybe by half. Once you start considering the value of your time involved, only you know if it's still a good deal.
I am always backed up on film development, so I usually take the stuff I'm being paid to shoot to the local pro labs. They do a great job developing the film, and I consider their charge when I give the client a price. Also I have a hard time getting my water to drop below 78 or 80 degrees F in the summer. So sometimes it's either the pro lab or wait for the fall.
Prints are another matter though. I have yet to find a lab that is interested in giving my prints the tender loving care that I give them. Most labs have a single contrast grade (high), and don't do burning and dodging. At least without really upping the price (often to an hourly charge). The difference between a machine print and a well done handprint is huge. I've had many clients change their minds about shooting the wedding or portrait in color when they see my BW handprints.
I think it's great fun. I think the real question is would you get more use out of a digital photo lab setup, and should you spend the money on that. I want to have both worlds, but I find magic in silver that I doubt I'll ever find in silicon.