I'm am not understanding how you pay for a deductible in advance on a claim that hasn't happened? Maybe I am missing something? If you do pay this deductible and have no claim, do you get the money back plus interest? Simple questions for a simple mind.
Last question first - no, you don't.
First question second - a buy back deductible is most often found in homeowner and commercial property policies, but you can find them anywhere. They are also pretty common in commercial trucking. For auto insurance, a Glass Buyback Deductible is pretty common. A buyback deductible is a provision that lets you pay a lower deductible when you have a claim that exceeds your original deductible. Buyback deductibles might not make sense at first, however, they're a brilliant solution to a common problem. Sticking with glass, let's say you have a comprehensive policy with a $500 deductible. A new windshield might cost you $350 or $450. You can reduce the deductible on your insurance by paying a much higher premium, of course, or you can keep your main policy the same and then pay a small deductible buyback premium and reduce your deductible for glass replacement only to $100 or lower.
If you are a homeowner with a $5000 deductible, a deductible buyback can reduce your first dollar losses from the deductible to $1000 or even eliminate it completely. And the combination of the premium for the policy with a high deductible, and the premium for the buyback deductible, is less than paying a premium for a lower deductible. Also, buyback deductibles are usually rather specific. Like, it may only cover the deductible for wind damage to the home, but not for fire or some other loss. Or for truck and auto, it may cover glass only.
In the case of cargo insurance with a $2000 deductible, a $26 a month ($312 a year) deductible buyback premium to eliminate the possibility of having to pay $2000 at a loss is certainly cheaper than having to pay the premiums on a cargo insurance policy with no deductible.