This display case for Lego mini-figures is being sold by a1 Toys for £6.50 via Amazon right now, reduced from the usual price of £12.99.
Suitable for children aged four years old and over, this mini-figure display cases is ideal for little Lego fans and perfect for storing and displaying favourite Lego minifigures. The display case holds up to 8 mini-figures and is stackable so you can collect as many as you can manage to house. It can also be wall mounted. Just push the release button to open.
The review for this are good - all four or five stars so far, earning a total of 4.4 stars out of a possible 5, and this is a pretty typical review:
"This is a fantastic product to display mini-figures. My son has his mini-figures on his bedroom windowsill and the downside of that is having to move them to shut blinds and curtains. With this display case they can be easily moved in one go meaning happy Mum and Dad and most importantly happy 10 year old as his mini-figures are not getting messed up and stay the way he wants them displayed. The only problem if you stack it is that you cannot open the bottom display as the button you press to do so is covered so I think this is a bad design if you are thinking of stacking and securing to a wall."
With thanks to wishihadadonkey at HUKD!