I checked into the NRA insurance 1.66 per $100 of coverage/yr.
So, for a $1000 gun 16.66/yr or replacement in 60 yrs. On the other hand if you have $15,000 in guns that's $250/ yr insurance.
I would assume that you'd be able to buy a decent safe for $2500 to $3000 or at 2750 it would pay for itself in 11yrs using the above info and you would not have the annual burden.
I guess its a function of how much you have to protect, but a safe seems like a better value and less headache. As long as you don't leave a cutting torch leaning against it!