I was going to say that sacks could be used like those bins- since they use a different kind of material, they'd have the advantage of opening the tech tree (slightly). They presumably would be limited in what they could hold, such as only allowing seeds or crops, or 1x1 items. It would be nice to store dirt or sand in a sack, for instance.
I kinda like the bins, but what defines what a different item is? Two different kind of coins? Two swords? Two weapons?
We do need a Barn of some kind to hold all these storage items, if only someone would take care of that...