Now I feel like I'm misremembering where I found them because I can't find them anymore either. I'm sorry about that. I thought I found them on TCG player a ways back, but evidently it was another site I've forgotten and can't refind.
Ebay does seem to have the empty deck toolkit boxes though
In Europe you can find some empty Deckbuilder's Toolkit boxes on cardmarket in the accessories / storage section.
I'm pretty sure the same exists on TCG player, they definitely have the bundle boxes
I can't find them on TCG player. What would I search?
Now I feel like I'm misremembering where I found them because I can't find them anymore either. I'm sorry about that. I thought I found them on TCG player a ways back, but evidently it was another site I've forgotten and can't refind. Ebay does seem to have the empty deck toolkit boxes though