1) the /sell command is part of essentials, but nothing has a price on the server files. and 2) something weird happened on the server as I was mining, getting and index out of bounds exception...
for ID -100... but my game loads just fine, it's when I join the problem occurs.
A LITTLE BIT LATER: and to go along with this, minecraft.net ddecided not to let me log in anymore from the launcher.
Minecraft.net is down, check this out.