I have never seen that style of container for takeout in my life and I spent two decades in the service industry. That's not common in America.
Still, for arguments sake that works out to about £.05 per box. Of course, that's if you go to the wholesaler to pick it up. If you're running a restaurant, you probably get it delivered with the rest of your dried goods. You pay for that, just like you pay for the cutlery and the napkins and the sauce packets and the bag it all goes in.
A buck really isn't unreasonable here. I've worked at spots where the takeout container was $0.30 each, and that's without figuring in the delivery/fuel surcharge.