'so invaluable' is a correct and usable part of a sentence in written English.
It is often used to emphasize the importance, value, or usefulness of something. For example, "The lessons I learned from my parents are so invaluable."
That's what makes Ms. Smith so invaluable.
"The rewards are so invaluable to everyone," he said.
The Indian casting director, Loveleen Tandan, became so invaluable to the project that Boyle insisted she get a co-director credit.
She became so invaluable that she eventually rose to a post at the Republican National Committee and, in 1976, the role of secretary of the party's presidential convention.
A high proportion of the children there speak English as a second language, which is why our volunteer reading partnership is so invaluable to them.
That's why Braingate is so invaluable; without it, the Sri Lankans might well have made it all the way to New York.
It has become customary for students and faculty of anatomy to create memorial services in honor of the donors from whom so much invaluable information is received.
I had my Tablet PC with me, so using invaluable OneNote and OneWord software I was able to post stuff as I went; such as musings on Bill's brilliant coinage "Creative Capitalism", and how it might possibly relate to the man walking ahead of me, pushing a supermarket cart piled with old tin cans and festooned with plastic bags, who couldn't seem to keep his trousers up.
After 31 years at the University of Chicago and so many invaluable contributions, it will be hard to imagine the clinic without his daily presence, said Director of Clinical and Experiential Learning Jeff Leslie.
Even so, it is invaluable for purposes of monitoring and spectroscopy.
"So it's invaluable for an out of hours service," Blacker says.
