npc problem

[Lbtg]

here is my npc

<?xml version="1.0" encoding="UTF-8"?>
<npc name="Pro Items Seller" script="default.lua" walkinterval="2000" floorchange="0">
	<health now="100" max="100"/>
	<look type="335" head="94" body="87" legs="104" feet="113" addons="3"/>
	<parameters>
		<parameter key="module_shop" value="1"/>
		<parameter key="shop_buyable" value="Pro axe,7389,80000000;pro Sword,11299,80000000;pro bow,8854,80000000;pro mage armor,8892,80000000;pro rpek armor,8883,80000000;Red Ghost Ring,7697,60000000;Pro rp boots,11233,80000000;Pro knight shield,7460,80000000;Pro mage helmet,2323,80000000;xazer rod,8910,1000000;xazer wand,8922,1000000;xazer axe,7456,1000000;xazer sword,7391,1000000;xazer crossbow,8851,1000000;xazer bolt,7363,10000;cigarette,7499,2000000"/>
	</parameters>
</npc>

problem is that
when plays says "buy 43535 pro mage armor" and npc asks if he want buy 100 of pro mage armos player says yes , and player gets 100 armors for free.
i using also Gold Nugget-100cc . added value in items.

please help

 

[Lbtg]

please help