Surprise! The /sell, /worth, /pay, /balance, and /repair commands should be back in working order now.
I've spent some time this evening completely rewriting the /sell price list. The prices now take into account (roughly) the rarity of the item if mined or the total value of the components if crafted. If you notice I've missed an item type that you think should be sellable, post it here. Also, after some hacking around in the raw source code for Bukkit and Essentials, I figured out the (apparently undocumented) way to properly list the items for sale that I couldn't get working previously (like stone steps, carrots, potatoes).
This of course means that I'll have to re-price all of the things currently listed in the marketplace, but that's OK because nobody can buy from the marketplace at the moment anyway.
