I recently got myself an M5 about a week ago and it works great. I got the prop itself from ebay.com for $30 plus shipping (which is a really great price)

It didn't come with any props though, so I had to find some myself. For some odd reason, my brother found a Chinese dollar, about the size of a quarter, and a Salvadorian nickel ( a little bigger than a penny). Both of these work great with the M5, so I didn't even have to go out and buy a steel-core quarter. The only down-side is that some people it is gimmicked because they are not familiar with the coins, though i say that there may be some "Chi" in the chinese dollar and that gets people going.
The order also didn't come with the wrist-strap, but I made myself one out of a wrist-band bought at the mall, so people think less of it.The one thing that concerns me is the noise it sometimes makes.
Either way, this is a great prop to use if you can find or make your own props. Everyone at school was completely amazed when I changed the Chinese dollar into a penny. Then they saw me put the Salvadorian nickel UNDER the penny, and with a wave of the hand, the nickel was gone, but the penny stayed in it's place. I also freaked out a waitress at a diner when I started moving around the straw wrapper.
I'm not saying that the props the M5 system come with are useless, I'm just saying that it really is important for a magician or an illusionist to improvise and make something still turn out fine.
This is my first review AND first post, so yeah.