As you said, all insurance companies are different. My best advice is to continue with your research, and go with the insurance company that satisfies your needs and price ( if the case is to lower your premium, and sorry if I am in the wrong way.) Every member here, have different insurance companies at their side with different monthly premiums, some are young and some are less young
. Good record and less good driver record, states, cities, color, marital status, renting, owning home, etc... Lots of variables on the equation buddy.
But my best guess is that in a common mean value, for a guy in his mids 20's will be paying a premium of 100-160 monthly.