I have Hagerty and pay $201.99 per year for $22,000 agreed value for the first car. Each additional car was only going to cost me another $50 to $75 per year because they say "once I have the 1st one, adding other cars is a lot cheaper"
Some of my friends have State Farm covering their collector cars cheaper but State Farm wants all of your cars and house before they give you a deal. So I've stuck with Hagertyfor 9 years. They have a limit of 3000/miles/year, no one under 25 driving , and no racing rules. I haven't priced American Collector though