Most aircraft manufacturers provide a document illustrating the operating costs for each of their models but it's hard to tell how accurate their estimates are (they are trying to sell you a helicopter after all). Furthermore the numbers they provide are usually for a certain utilization level. In the case of a Robinson, that level is 500 hours per year which is much higher than most personal operators will ever achieve.
To provide people with a better estimate of the real costs of helicopter ownership I've created this tool that gives you numbers specific to your operation. The model used to perform the calculations is based on a combination of official information from Robinson, operating statistics collected from owners, and real maintenance figures from overhaul shops.
Note: Total costs include the overhaul reserve. Because of this high time ships may appear significantly more expensive to operate. Remember that much of this cost is offset by the lower purchase price of that ship. To see how much it will cost you to operate after it's been overhauled, reset the time and age to 0. All prices are US dollars.