Without seeing the code I cannot tell you exactly what to do, but search for the sql query which would be something like this:
SELECT * FROM listings
ORDER BY price
LIMIT 1,10
As djjjozsi said, you will use ORDER BY to set by which field you want to sort. Add ASC or DESC to the end of ORDER BY [fieldname] to set if its ascending or descending. In this case it would be descending so:
SELECT * FROM listings
ORDER BY price DESC
LIMIT 1,10