I was fed up off having boxes of straps, unsorted, so I bought a couple of these from AliX. There's a lot of different types available. AliX were less expensive than eBay, as is normally the case. These have 4 compartments like this. They butterfly out, so there's 2 10-up sections, but there's 2 zipped sides each with 2 sections, so a maximum of 40 straps. A few less if you use the whole width for a bracelet, say.
It was when I filled this that I realised I had bought 2 22mm white straps instead of a 22mm and a 20mm.
I've just ordered another one now in a different colour.
It worked out at exactly £16.00 incl VAT.
) and it's great, although it's full now so I could do with another!