I’m looking for an English word which could mean something or someone that adds value to something else. Is there a single word for that?
Enhancer or Enhancement
From the word enhance: to make greater, as in value, beauty, or effectiveness; augment; to provide with improved, advanced, or sophisticated features.
This would satisfy the request for a word that applies to something that adds value to something else. But I don't think I've heard it used to apply to a person who adds to the value of something.
What of Asset which is a currency exchance for value?