I love these storage boxes and the small boxes inside are fantastic for my seed beads and will hold up to 25 grams of most seed beads. The larger box comes with 24 smaller boxes and I love the flip top closure they have. Once in a while you will find a box that doesn't close super tight and if you put your 15/0 beads in one that doesn't close like it should, you could lose some if you turn them upside down . I have found that most close just fine so unless you use all 15/0 you should be fine.
Harbor Freight is an awesome place to pick up odds and ends items, I even found a jewelry hammer and anvil there! I love to browse their stores because you just never know what you'll find. I've not ordered from their website as of yet, so I cannot speak for that, but I've shopped in store a lot and it's always been a pleasant experience.
This storage system may not be for everyone, but at $4.99 each, the price is definitely right.