The Lego helmets look sick, I'd like to pick up a few at some stage.
You could make up a few corner shelves, and put them up the side of one of your rooms if there's space, and have it measured out to fit one helmet on each shelf. I did something similar in my bedroom, and have one for my controllers, another for my subwoofer, and the top one for an old WW2 gasmask I got.
I've spent a fair bit over the years on my collection, and this is only some of the stuff I have. Most of my other stuff is in storage boxes, and this stuff was sitting around in boxes until now where I can finally have it displayed.
I'm not too sure what price I'd put on the stuff, the helmets were about 150-200 each, but since being discontinued, they've gone up in price. Last time I checked, Darth Vader was about 500 Euros. The figures are in varying conditions, but I'd say they're going for 5, 10, 20, and some maybe 30 each. I need another 26 or around that to finish the whole collection. But, there are also the final 17 figures which came out in 1985, or 86.