value/ˈvæljuː/
The winner will receive a prize to the value of 1 000.
Take things of value with you when you leave.

The lunch special is really good value. I bought the phone at a good price.  It is really value for money.
 
He didn't say anything of value.    
The book's value to me is great.
Fruits of high vitamin C are of high nutritional value

I really value him as my best friend.
He's a valued member of our team.


Valuable


 
I have a valuable collection of stamps


 a valuable experience/lesson
The book provides valuable information.

invaluable
invaluable information
The book will be invaluable for students in college
 His knowledge of the area made him invaluable.

Valueless 
 adjective
Such data are not valueless,.

Worthless 
 adjective
His paintings are worthless.

priceless
priceless information （invaluable information）
Our family photos are priceless.