I also have State Farm Personal Article policy which covers guns, jewelry, antiques, collectables and camera gear at about the same value you have.-----your quote sounds reasonable to me. I am paying about $30 a month for mine, but I also include that with my auto insurance premiums so the multi-policy discount drops the price a little.
A word of advice, after you send your insurance the inventory and values, Make sure you have your insurance send you a list of what they actually have on file in their system. I notice the price of my insurance went up after deleting some items off of my policy----after inquiry, I discovered that the insurance company had many of the same items double and triple listed while not having some of my new additions on the policy----So, my advice is work with your local insurance agent to make sure you have a good method of adding and deleting items from the policy.
I am a 30 Year State Farm customer and have nothing but good things to say about them---all of my auto claims have been fair and painless and..... I even had a $1000 Camera lens roll off my countertop onto a ceramic tile floor---and, well that made the lens all jingly on the inside. I called and got an email quote from Canon, sent that to My State Farm agent and had a check for the full amount of the repair two days later. Hard to beat that for service and peace of mind.