@Elsa Mist i have test for this no problem
i think your checking
if you change ID 30000 & 30001 is already
1. check item db ...\db\import-tmpl\item_db.txt
// Vending system
30000,Zeny,Zeny,3,,10,10,,,,,,,,,,,,,{},{},{} <-- change you want item id
30001,Cash,Cash,3,,10,10,,,,,,,,,,,,,{},{},{} <-- change you want item id
2. check battle conf ...\battle\feature.conf
// Item ID for Zeny. Set to 0 if you don't want use Zeny.
item_zeny: 30000 <-- change you want item id
// Item ID for Cash. Set to 0 if you don't want use Cash.
item_cash: 30001 <-- change you want item id
3. check you data file ...\data\idnum2itemdisplaynametable.txt
// Vending system
30000#Zeny# <-- change you want item id
30001#Cash# <-- change you want item id