BuyNode Error

11:45:40 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'buy' in plugin BuyNode v0.1
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:168)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:492)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:878)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:825)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:807)
	at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:44)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:276)
	at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:109)
	at net.minecraft.server.ServerConnection.b(SourceFile:35)
	at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:581)
	at net.minecraft.server.DedicatedServer.q(DedicatedServer.java:212)
	at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:474)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:406)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)
Caused by: java.lang.NumberFormatException: For input string: "[10]"
	at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1241)
	at java.lang.Double.parseDouble(Double.java:540)
	at ca.docilecraft.BuyNode.addPerm(BuyNode.java:99)
	at ca.docilecraft.BuyNode.onCommand(BuyNode.java:34)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 15 more