This is a charade - multiple separate clues that combine to form the complete answer when placed together in sequence.
Break this into parts: 'money for Americans' gives you the first part (think slang term), and 'short notice' means an abbreviated form of a word meaning notice or attention.
Answer: BUCKSHEE | 'Money for Americans' = BUCKS (slang for dollars) + 'short notice' = HE (abbreviated form of 'heed', meaning notice/attention). BUCKSHEE means free or at no cost.