If you run Octane Bench to test your own machine, it will give you a relative render horsepower score. So, for instance, let's say your machine has a score of 50, and after doing some test frames you figure that your machine would take ten hours to complete the job. A single Octane Render Cloud OB unit of render horsepower is 100, twice that of your machine, so it should complete the job in about half the time, or in five hours. If you use two ORC units at a time, it should be done is about 2.5 hours, etc. Regardless, you are looking at about five total OB unit hours of work, however you choose to apply them. At $0.024 per minute, you're looking at about $7.20 total render cost to run your job, assuming your local test render gave you a pretty good render time approximation.