I don't know anything about a Thievery top, maybe I missed it, but I did steal some +2 Thievery gloves off of a dwarf who scammed me, so I can have probably 7 Thievery.
I was actually right at exactly that point in the fishery. The fight went quite well with my extra armor, although it was only 37% of a level.
With the money from selling the enemy drops rewards from that and the lost ring quest, I got back up to about 12,000 gold again. I even found a skillbook which was not useless, shocker of shockers.
So it seems like I can postpone my gold worries for later.
