No RVs are the same. The one I am looking to buy a share in is a 6 with a 160HP O-320 and fixed pitch metal prop. NVFR steam gauges with Garmin 430. In the lower altitudes, you can run it 28 lph for 140KTAS. Still need to fly it up to 9500 to see what it does there, but the previous owner suggests 150.
So if you want to get from a to b, it need not be more expensive in fuel burn than a recreational type, except you do it 40-50 kt faster...
Unless there are any parts to replace, an independent LAME away from the major airfields can do the 100-hourly at about $1000; a figure I hear from many owners.