Like many I have bought figure cases from the likes of Games Workshop and loose foam trays from Figures in Comfort or KR. Many of my trays are stored in zip up boxes I bought from Ikea.
The ones I have are called LYCKLIG, I can't see them online but they have something similar called FLÖRT which might be suitable and comes in 2 sizes (£4.49 and £5.99), they are meant for CD/DVD storage. Check they haven't messed with the sizes too much before shelling out. Then start queuing for the cheap ice cream!