Cola Cap Prediction by Top Hat Magic

NOTE: This is used and in like new condition. 
It came from a magician's estate. 

Seven cola bottle caps are shown.  All are normal black cola caps.  Tell your helper this is a game of chance.  Caps will be eliminated one by one until only one cap remains.  They get to keep the discarded caps and you only get last cap.  The caps are now mixed showing the tops of the caps only.  Now a game is played eliminating caps one by one until only one cap is left.  The cap left after the elimination process contains the money inside the cap and all the other caps are empty inside.  

Instructions included.