>>2542072The German Army Rucksack from the OP photo is the only option in flecktarn. It's 65 liters, more reasonable than 35 liters for three days trips. It's quite uncomfortable and distributes badly the weigh. Other options in german flecktarn are knock offs copycats from Miltec/Alibaba sweatshops. Your call if you want so bad a backpack in that cammo patern and that budget.
Also, you can try the Belgian paratrooper backpack in their own flecktarn pattern. IIRC it costs 50 bucks. Less-sucking ergonomics and still viable for three day trips.
If you don't mind the flecktarn pattern, there are much better options at that range of price.