Okay, looks like pretty much everything is actually server-sided.
[code]001 [001000000005BE6C] Long : 4503599627746924
002 [..............01] Byte : 1
003 [........0000000A] Int : 10
004 [................] String : 50000 Gold
Upgrade Stone 1
005 [................] String : Magic Attack
006 [................] String : :
007 [................] String : <color=3>+68</color>
008 [................] String :
009 [................] String : Chance of Success:
<color=7>100%</color>
010 [................] String : Upgrading to Savage Ice Wand level 5.
If the upgrade fails, the item's upgrade level may decrease.
Proceed?
011 [................] String : Upgrade
012 [................] String :
013 [................] String : SType 5 Level[/code]