Pretium nostrum est!
Minime! Ad Mordor id portare debemus.
Illi ad Isengard hobbiti captant!
Not "Est pretiosus nostrus"?
"Pretium" is rather "price, value" I think, and "pretiosus = precious, as we talk about an "anulus" being masculine, I let the -us declension.
I tried the pretty ring - it was not accepted - but would it be correct?