Not much if you consider that are quite structured, and half the price :)

https://matadorup.com/collections/hiking-mountaineering-packs/products/beast28-ultralight-technical-backpack

28 liters / 680gr / $150

Unlucky they don't have > 28 liters models, so we have to compare to the 40 liters ones.

https://www.hyperlitemountaingear.com/products/2400-junction

40 litters / 878gr / $349

These are full water proof? I read: "Pair with our Stuff Sacks for a buttoned up, nearly waterproof kit."