Adjective : an invaluable art collection; her invaluable assistance.    From Dictionary.com. 

Sallie, wishing to impress me with her invaluableness, did her absolutely Southern best.    From Wordnik.com.  [Dear Enemy] Reference

A handful of students from the Project Connections program at Middlesex County College came to speak on the invaluableness of the program, which is to be cut.    From Wordnik.com.  [East Brunswick Sentinel] Reference