Not sure what you mean by reasonably prices, but I have used Collectibles Insurance Services for several years. No losses or claims yet, so can't comment on their claims service. I carry about $70k for around $450.00 per year. That covers my collection while they are in the safe, on display, or in transit by vehicle or common carrier - also covers the attendant bayonets. They absolutely cover everything your homeowner's insurance does not. Their website is insurecollectibles.com.
They insure collectibles only and do not cover damage from firing the weapon. If you want coverage for modern firearms, use the NRA insurance which is somewhat higher.