You've found South Side Sandblasting (neighbors with, but not directly associated South Side Red-E-Mix).  I have been blasting for about 5 years now.  I have experience with everything from bar stools to entire cars.  I use -30 sand from the Kaw river that has been graded and dried.  It makes a great surface to paint.  It is the finest sand available.  Coarser sand removes rust quicker, but leaves deeper pits and warps thin metal easier.   I charge $50 an hour.  If you check around, you'll find this quite reasonable.  I go by the hour meter on my compressor, so I don't charge unless it's running. I offer portable blasting around the Warrensburg area for a higher fee.  If you need blasting done, contact me - drew@drewswhips.com  some videos of interest... unloading 25 tons of sand- http://www.youtube.com/watch?v=cbOdI1wp8ds blasting a tractor bucket- http://www.youtube.com/watch?v=6EtXWRyuoSw
Old bird bath and sign, pretty bad shape...
looks a little better The sign took about 15 minutes and the bird bath was a little more
Notice the detail under the rust and paint.
Old chairs that cleaned up nice
60's Dodge Challenger fiberglass on the bottom rear panel
this was a six hour job