I think it is Glad that now has a line of boxes/tubs that are plastic with a tight seal and sold as disposable.
I love the ones that my sister sends my cake and cookies in, as they travel well and LOL, wash well and seal as tight as the old Tupperware was said to seal and never did for me.
Yes, on the dollar store as a good source for odd and often very interesting items.
Of course, you could get busy and make baskets.