Single word alternative to "overvalue"
Solution 1:
You can overrate something or overrate the importance of something.
Overrate:
have a higher opinion of (someone or something) than is deserved
Solution 2:
How about overweight?
overweight :To place excessive weight or emphasis on; to overestimate the importance of
Solution 3:
Overemphasize — "to place too much emphasis on or employ too much emphasis".
That's what you did in your example at least.
Solution 4:
I exaggerated the importance of X.
I ennobled X.
I aggrandized X.
Are some suggestions, if you want to avoid the over- prefix.