Ask around your neighbours, lots of people have stuff shipped from abroad packed in those.
Or the actual shippers/receivers will sell you one for sure .
Life tip : when you do get your hands on one, don't forget to drill holes in the bottom of them---- so you dont end up with lots of smelly water in the bottom when it rains .
It also makes them less " valuable" , as it is not unheard of them wandering away.