Magician displays a normal half dollar face up in his right hand palm.
 
You then comment about inflation and how money is losing it's value. Go on to say that you never really understood how inflation worked until a friend explained it to you.
The coin is then visibly transfered to the left hand palm and the fingers closed around it. A straw is then inserted into your fist and you blow air into the closed fist (this is "inflation").
Slowly open your fist to show the face of the coin in 3 dimension! 
Now that's INFLATION!
Great close up coin effect that looks professional and is easy to do.