How did you get all the preciousmetal doujins that you have and where can I find them? What stores in Japan sell them?
Knowing Japanese helps me with auction sites like Yahoo. I have been collecting doujins for years  and preciousmetal since.. 2016, so it isn’t like I bought them all at once. I have a friend in Japan nowdays that goes to events and stores and grabs them for me directly. Other than that, you can find many doujin stores on the net and order them via a proxy which is a long explanation… Here, let me help. There is a doujin event called Comic City next month that are in a few confirmed that are new releases too.
ライヒビ [RiHibi] or ヒビライ[HibiRi]= huntershipping. Very rarely ライ can be replaced with シル. That makes it HibiSil or SilHibi.
ゴシル [GoSil] or ゴシル [GoSil] = preciousmetalshipping.
同人 is doujin.
Good luck and happy hunting. I am confident you will find something because doujin stores frequently stock and usually run by buying off unwanted/used ones. So check periodically.