User blog comment:Halo Monkey/Models/@comment-4503347-20120815030946

These are resin kits, which usually have rather dull looking packages so they're pretty normal. Doing a quick search on Google shows that they were of limited release which goes way back to 1999.

Some models and decals are also released recently in the form of event-only limited items, like these ones below:

http://www.geocities.jp/puramoyamaguchi/wf2008s/index.html