dry bags

Aren't those more expensive? This is two five gallon bags for ten bucks. So

Cheapest dry bag I saw on amazon was 14 bucks for five gallon. That's three times more expensive.

https://www.amazon.com/Grassman-Waterproof-Ultra-Thick-Lightweight-Swimming/dp/B08DNPQWWJ/ref=sr_1_9?dchild=1&keywords=large%2Bdry%2Bbags&qid=1622145205&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-9&th=1&psc=1