Have you tried something like this?
http://www.instructables.com/id/Photography-Light-Box/
I’ve never done it. I know it’s popular for Legos and other stuff as well such as Ebay items. I know you can buy the boxes at places like Amazon for under $50, if I remember correctly. I’ve also seen plenty of flickr pics where people (and by ‘people’ I mean ‘Lego builders’) rig up their own using sheets and desk lamps. I don’t have time to research it now, but I know there’s a lot of options and as far as I can tell, it’s a very cost-effective way to take quality pics and the only limitation is fitting your item inside the box.