When to get Zed’s Demise

Merchants have a basic inventory that never changes that consists of common and miscellaneous items, but their uncommon and up inventory changes.

I don't know the exact details, because it seems fairly random due to sometimes them changing when I leave for 1 second, and sometimes not changing for 10 minutes.

I'd hazard a guess at one of the following, and I'll clear this up once I've researched it more:

1. It's similar to dead bodies despawning in that if you can't see them for a limited amount of time, then they despawn, maybe you just have to leave the immediate area for x amount of time.

2. I think this is the more likely one, perhaps there's a hidden timer that causes them to change their inventory similar to the special deals in Borderlands. Say every 15 minutes the inventories change, whether that's 1 minute from when you see them, or 10 minutes from when you see them.

There's no other way of gaining skill points other than leveling up, which only grants one skill point.

So the amount of skill points you would have at level 60 would be 59.