upgrade item effect - confused

[toycar]

i am baffled with the following workbench items:

 

Targeting Scope Mark I

• Required Skill to Craft: Stealth (8)
  
• Component Cost: 5
  
• On Hit: Stun, 25% for 2 Rounds
  
• Save: DC 14 to negate stun
  

Crippling Scope Mark I

• Required Skill to Craft: Stealth (10)
  
• Component Cost: 12
  
• On Hit: Stun, 25% for 2 Rounds
  
• Save: DC 10 to negate stun
  

 

Why would Crippling Scope Mark I be more expensive while it is less effective?

(a die roll >= 10 would negate it while Targeting Scope Mark I require at least 14)

 

EDIT: nvm, in-game description is wrong, Targeting inflicts slow instead of stun