Web Sack can be sold for 45,000 gold, due to two bugs. The base price is 15k, which is out of line with other wands--I'd suggest something in the neighborhood of 7,000 gold. The extreme price markup is really due to the over-charging of the wand. The item file shows one charge, but it's being given with 10 charges: GiveItemCreate("wand14",LastTalkedToBy,10,0,0) from sppain.dlg. If we up the charges in the item to 10 (or more) then the extreme markup should go away.
Second issue are the two sewer cleaners. They both use adventurer animations and come equipped with swords and shields; I don't recall anyway you can end up fighting them. I suggest they use default commoner creatures with no equipment.