Teddahlia I use these exact same crates. I have them in three different heights and they all stack with each other. They fit 15 32 oz deli containers for starting tubers. I use the 8" height for starting and stacking and once they out grow the stacking i move them to the taller crates. I live them.
I bought them fb market place for $5 each.
Oh and they fit in my wagon for bottom watering.