Not trying to pulg any insurance company here but I have two Cobras with full coverage on them and one of them is a 1969 Torino Cobra like they raced in nASCAR and there were just 29 made in the configuration that mine is. I do have a 3,000 mile per year restriction which I can have raised but the 69 still has the original Polyglas tires and I don't approach the mileage limits. Mine went up this year for the first time from $775 a year to $802 per year and that is for both cars. The replica has an agreed value of $45,000 and it doesn't appreciate over then years. You can use this as a price comparison to what you are paying and it may help.
Ron