I am in HO scale so need different dimensions.
Recently I went through Bunnings etc looking for some new storage for my things. When I looked at Officeworks the plastic ones there looked very poor quality.
I have storage crates that are 20 plus years old and I stood on one recently to reach an upper shelf. No problems.
I have some that are maybe 10 years old and they are beginning to disintegrate.
5 year old ones are cracking already.
The Chinese made ones are mostly made as cheap as possible now so consider the future when buying. The quality is not what it used to be.
I am in Adelaide and Viscount plastics have a presence here still and I think there is Richmond storage who sell all kinds of storage, wheels etc that I got some things from years ago.
If you tell us where you are somebody may be able to shed more light.
Is there a reason you want plastic? Things like wooden boxes can be made to stack very neatly to maximise contents. https://www.davidjones.com/Product/20049878?istCompanyId=466a8370-6b00-4f27-87e1-ca6839e80dd6&istItemId=-xprliaxali&istBid=t&gclid=CjwKCAjwo_HdBRBjEiwAiPPXpHMkL_Ms9pSEl_EEhMDezyANbwuvkGA6U0SOyNQATL6FtsTOiPqFIhoCncYQAvD_BwE&gclsrc=aw.ds
Because of N being smaller I did a simple search on google for Jewelery storage box and found the above link.
Wooden storage box may find something suitable for you, or check around the markets and wood working shows. That is if you do not have to have plastic as the wood will last a lot longer.
If you get a large open wooden box it is easy to use ply or masonite to make some shelves, and you can set them at the height best for you.
Say 15mm for flat wagons, 25 for box cars and maybe 30 for locos etc.
Lately I have been getting cardboard trays ( avocado, strawberries etc from the markets and using them to place my trays into.
They stack neatly and different colour boxes for different items. ( black ) locos, green carriages etc. I just staple some paper on the ends to describe contents of each one.
If you make individual trays you can add some fabric into them to protect them from the scratching of wood or cardboard. A remnant of fabric from a habadashery store will cost almost nothing.