J'en vaux vraiment la peine vs Ça vaut la peine

Question

Bonjour! 
Why does "J'en vaux vraiment la peine" have en whereas "Ça vaut la peine" doesn't? I've encountered the latter phrase before but with en (i.e. Ça en vaut la peine). 
 
Will appreciate further clarity on this :)
 
Merci!

Accepted Answer

Bonjour Chesca,
It is an idiomatic 'en' here. 
Please follow the links below for a more in-depth explanation:
en-vaut-la-peine   -   j-en-vaux-vraiment-la-peine
I hope this is helpful.
Bonne journée !

Answer

This is an odd sentence in any language. Maybe rewrite it? People don't really say that to each other, do they, unless they're like in a vicious relationship...? I say this with all politeness.
Vous ne valez plus rien !You're not worth anything anymore!

Answer

Bonjour Katherine,You're absolutely right! It's quite mean. Thanks to you, this example has now been changed to something more positive ;-)I hope this is helpful.Bonne journée !