I buy 25kg sacks as required, plus I grow other varieties (red and Spanish).
I make up BIR (British Indian Restaurant) base gravy for homemade curries, usually about twenty 500g packs per session.
Plus I make bases for French Onion soup that I freeze in batches too. And Italian style sauces for pizza and pasta.
And I also dehydrate onions for flake or powder.
Some packs slowly sink to the bottom of our chest freezer, only to be found when I do a total defrost once a year or so.
We like onions in this home.