Looking for HB Payday 2 Mask Packs

So, I got Payday 2 on sale a couple days back, and I've been reading the wiki about the in-game masks and found out I had two mask packs from some humble bundles I bought some time ago, namely the "Lycanwulf and The One Below" and "Orc and Crossbreed".

Being the collector I am, I'd like to get the other two existing packs, but I don't really know where to begin or what would they be worth for in a trade...

Would you guys have any guidance for me on this? :3