What's a four-letter word that has something to do with the word or being priceless.?

I am currently in 8th grade. I have been credited in my school year work. Now I have been accepted to do private summer school. I am stuck in a crossword puzzle. Their is no theme set on the puzzle. Now, a 4-lettered word that means priceless, or has something to do with it. Thanks for your help and time!~