I'm not sure if it's a Vault or an BoseConomy issue but read by yourself:

[SEVERE] Error occurred while enabling SimpleRegionMarket v3.3.0 (Is it up to date?)
java.lang.NullPointerException
at cosine.boseconomy.BOSEconomy.getMoneyFormatted(BOSEconomy.java:1073)
at net.milkbowl.vault.economy.plugins.Economy_BOSE7.format(Economy_BOSE7.java:155)
at me.ienze.SimpleRegionMarket.EconomyManager.econFormat(EconomyManager.java:124)
at me.ienze.SimpleRegionMarket.signs.TemplateMain.getReplacementMap(TemplateMain.java:156)
at me.ienze.SimpleRegionMarket.TokenManager.updateSigns(TokenManager.java:94)
at me.ienze.SimpleRegionMarket.TokenManager.checkRegions(TokenManager.java:249)
at me.ienze.SimpleRegionMarket.SimpleRegionMarket.onEnable(SimpleRegionMarket.java:110)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_5_R2.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R2.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_5_R2.MinecraftServer.j(MinecraftServer.java:303)
at net.minecraft.server.v1_5_R2.MinecraftServer.e(MinecraftServer.java:282)
at net.minecraft.server.v1_5_R2.MinecraftServer.a(MinecraftServer.java:242)
at net.minecraft.server.v1_5_R2.DedicatedServer.init(DedicatedServer.java:150)
at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:381)
at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)

[BattleArena] Error setting currency name through vault
java.lang.NullPointerException
at cosine.boseconomy.BOSEconomy.getMoneyName(BOSEconomy.java:962)
at net.milkbowl.vault.economy.plugins.Economy_BOSE7.currencyNameSingular(Economy_BOSE7.java:120)
at mc.alk.arena.controllers.MoneyController.setEconomy(MoneyController.java:77)
at mc.alk.arena.listeners.BAPluginListener.loadVault(BAPluginListener.java:247)
at mc.alk.arena.listeners.BAPluginListener.loadAll(BAPluginListener.java:85)
at mc.alk.arena.BattleArena.onEnable(BattleArena.java:121)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_5_R2.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R2.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_5_R2.MinecraftServer.j(MinecraftServer.java:303)
at net.minecraft.server.v1_5_R2.MinecraftServer.e(MinecraftServer.java:282)
at net.minecraft.server.v1_5_R2.MinecraftServer.a(MinecraftServer.java:242)
at net.minecraft.server.v1_5_R2.DedicatedServer.init(DedicatedServer.java:150)
at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:381)
at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)

Greetings, Androkai

at cosine.boseconomy.BOSEconomy.getMoneyName(BOSEconomy.java:962)

BOSE issue, or possible with how you have it configured. It should return the name of the money. if it's not, check your setups. If it can't be setup check with them.