Personally, I thought Skuldoon had every katal to buy except for the Dried Homonculous. You might be correct (probably are). What you need to do is get one Shrunken Head, then sell it to a merchant, then you can buy all the little heads that you want.
I just figured that out today. I've been making money in Arindale mixing Summon Warlord and selling it back for $200 profit. I just realized I sold them all the first katals (at The Temple of Empyrean). I get much more money for stuff in Arindale than anywhere else.
