Supply Rolexes – prices essentially will be higher still (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

An anagram (‘supply’ – adverb from supple) of ‘rolexes’ plus IC (‘pr IC es essentially’). The Latin motto of New York State (and currently appearing on its new car licence plates), and (probably hence) the title of one of the more ridiculous poems, by Longfellow (“The shades of night were falling fast”…).