Are the Ninja, igloo cool boxes worth the money? Are there cheaper alternatives? We only camp for 3 or 4 days at a time, we have a camper and we do have electric hook up and a Jackery portable power bank. But prefer not to pay for hook up. We could do with a cool box just for Milk, Bacon, cheese etc.. but there are so many on the market. Obviously some are very expensive including the Ninja and Igloo. Are there and alternatives or is it worth paying more?