Let's see...
Crossroads I has 6 major NPCs with anywhere from 6 to 60 lines of conversation each. I think the most was my innkeeper, who had about 60 lines with multiple branching trees (it was his job to give background on the surrounding area and information about opportunities for adventure). Two quests, both of the "get this item for me" type. Four merchants (although two of those are for the same NPC, one just a "beverages" store and one "arms and armor" store). Plus I yoinked a nice script for generic NPCs that gives a random one-liner response from a list of twelve possiblities. I use that for tavern patrons, miscellaneous travelers, etc.
I also have a number of custom-created NPCs that I keep in the palette to paint if I need somone to quickly possess and interact with the PCs. In C-one I had a low-level ranger, a lantern archon, and a generic merchant in this category. You can use the generic creatures in a pinch but I find it's more effective if the NPC has a name (and maybe a few specific abilities/items). In my last game, for instance, I beamed in the lantern archon, shadowed the party for a while, and when they finally noticed him (after a battle in which he cast aid on several characters), he spoke to them and gave them a quest to investigate a nearby ruined temple. After they had completed the mission, I respawned him and gave the PCs rewards using the DM tools in-game.
Crossroads II has 5 NPCs (its base area is the same as C-one, so several characters were returning NPCs with new conversations), three quests, and several new and modified merchants.
I like to script out at least the basic NPCs (innkeepers, merchants, quest-givers, etc.) at the "base" area so that I can focus on actually running the game. Plus I would ultimately like my mods to be playable as SP games without a DM. I'd say each took about 40-50 hours of work on the toolset to complete.