Most important, IMO, is to remove the wheels from the splines every year, so you can clean and lubricate the splines. Otherwise they tend to seize up until they cannot be removed without ruining both wheel and spline extension. While you've got them off, check that the special nuts that hold the extension to the hub are tight.
Also check the spokes during your annual service. Tap on them with a small wrench or similar, they should ring. If you just get a "thud", that spoke is loose.
Easy check for trueness is to spin them with the car jacked up. Watch the rim near the tire for wobble, but ignore any small dents like at a weld seam.
Dunno what a shop would charge for a "tune-up" (obviously depends greatly on the condition of your wheels, how many spokes they have to replace, etc.). But I'll bet it ain't cheap !