Sorry I'm late responding.
This is a niche item....designed for heavy use in extreme conditions. I'm retired and camp a lot....a LOT. These boxes are rugged and very well made. If you'll only use them two or three times a year...you may want to seek a cheaper alternative.
I'm guessing these were government surplus based on the stickers that were attached.
I chose the small size because it fit my trailer perfectly. I've found that I can leave my food and gear in the cases....and left outside the vehicle at night....safe from critters and rain....with the exception of camping in bear country. The hinges are strong and the latches are lockable.
I've also found that they make great furniture around camp. Prop your feet on them....cook on them if you desire. Double stacked and they are a workable height.
So for me....it was a great deal considering the retail cost....for some of you...maybe not.
Hope this helps.