Oh ok
. With bin cages you can stack them on top of each other
If there is plenty of ventilation in the sides. I was also looking at shelves recently and one idea that occurred that is cheap (although possibly tricky) is to just stack bricks on top of each other and put a piece of wood, cut to size, over the top. People used to do that to fit old belfast kitchen sinks. Pile up a couple of rows of bricks and sit the sink on top so it was the right height to the work tops.
Tricky in that not many people have bricks available! Ivar shelves sound more attractive.