How to say "It Is X Dollars" in Chinese:

"X" kuai4 qian2

What are these numbers? 

"X" = (the dollar amount in Chinese numbers)
kuai4 = a counting particle meaning "a piece"
qian2 = money

For example, It's 5 dollars in Chinese would be "Wu3 kuai4 qain2" with Wu4 being the Chinese word for "5".