Small problem with the NPC trade feature

[Nubs]

I made an NPC to buy nearly every piece of equipment, but quite a bit of it is not showing up in the trade feature. Is there a limit to how much can be in it, or do we have to change was it allowed to be sold and what isn't somehow?
And, it's still the same basic loot buying NPC that comes with the Crying Damson server, just with all the extra items added.

Magic Plate Armor and Brass Armor are just 2 of them. Figured I'd see if something was wrong with them in the feature, or if I need to change something. +rep for anyone who can help me! Been messing with this stupid NPC for the past few days.

 

[Elvang]

        <parameter key="module_shop" value="1"/>
        <parameter key="shop_buyable" value="helmet of the ancients,2342,50000;devil helmet,2462,3500;warrior helmet,2475,7500;strange helmet,2479,1000;crown helmet,2491,5000;crusader helmet,2497,8000;plate armor,2463,800;golden armor,2466,30000;knight armor,2476,13000;crown armor,2487,10000;dragon scale mail,2492,90000;crystalline armor,8878,85000;voltage armor,8879,85000;swamplair armor,8880,85000;windborn colossus armor,8883,130000;oceanborn leviathan armor,8884,130000;golden legs,2470,150000;knight legs,2477,3500;crown legs,2488,35000;plate legs,2647,1000;boots of haste,2195,30000;steel boots,2645,30000;fur boots,7457,5000;"/>

 

[Nubs]

Thanks, but I've got the basic concept for the NPC. It's completely set up, no errors in the script or anything, it just won't buy certain items. Is the trade feature limited to buying items that are in quests or starting items, or is it something you have to change?