This box is IP rated and airtight, perfect for storing 5 x 1kg rolls of filament (or smaller), and costs $15.00.

My printable insert enables the rolls to stand up neatly inside, wrapped or unwrapped, and provides space for a desiccant pack.

The insert is designed for these DampFree slim desiccant refill packs, which are $8 for a pack of 3, and also available from Bunnings Warehouse:

https://www.bunnings.com.au/dampfree-moisture-absorber-slimline-refill-sachets-3-pack_p0011484

The desiccant packs fit in the space directly under the rolls of filament, and are easily accessible if they need to be changed.

At 5 rolls per box, this is an easy to handle and nicely scalable solution, and each box is less than $20 in total - You can make 2 boxes, which will store 10 rolls for $38 Australian dollars, and have a spare desiccant pack, or make 3 of them and have 15 rolls of storage space for a bit over $50.

The print is split into 4 pieces for ease of printing, and the locating pins are a friction fit, but can be secured with some glue if you'd prefer.