You don't get for nothing
You don't get something for nothing.
Prov. Everything costs something, and anything that appears to be free must be deceptive. Jill: This newspaper ad says we can get a trip to Hawaii for free. Jane: There must be a catch to it somewhere. You don't get something for nothing.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.