You may not need a baitcasting rig, but they have uses that a spinning set up can't touch. They can be used for nearly all of the same lures that you might use on a sppinning rod, minus the super small cranks. Spinnerbaits, crankbaits, topwater, jigs, everything.I Guess what I'm saying is that they can be just as versitile as a spinning rod. If nothing else it fits in nicely with an all around arsenal.
Like Gavin said, fly rod, bait caster and spinning rod. I like to have an assortment even when I'm wading or cruising the banks. I always prefer to throw metal with my baitcaster and small to medium plastics with the spinning rod.Oh yeah, flukes on a spinning rod are a blast.
You can get a nice starter setup with a Pinnacle reel and a Lightning rod. Pinnacles are easy to set up and the Lightning rod is super sensitive. Both for under or close to a hundred bucks. Then you only need to decide on which line you want to put on it. That's been beat to death so you are on you own there.
Go ahead and take the plunge Jack, you will not regret it.