The sign for "expensive" is a combination of a single movement of "MONEY" and "throw down.
(Think of "throwing money away.")
Slap a flattened "O" hand onto the left palm, then lift it off and
throw it down as you open the hand into a loose handshape.
Note: If you do happen to feel like throwing money away,
might I recommend that you instead put your money to good use and
donate to Lifeprint.com? -- Just a suggestion.
You can learn American
Language (ASL) online at American Sign Language University ™
by Lifeprint.com © Dr. William Vicars