As an undergraduate, Engineering Economics was a requirement. I still remember a seeming silly question, "How much would you spend to recover a loss of $12,000." All of the equations about interest rates and the such didn't give an answer; but, common sense tells us $11,999. That way you get at least something back.
Let's look at your question from the same standpoint. If your 870 is stollen, then it will cost you $300 to replace it. If your $1,200 Benelli is lost, then it will cost you $500 (your deductible) to replace it.
What's a better deal, a new $300 870 for $300 or a new $1200 Benelli for $500?
Take the gun that you shoot best and leave the rest.
