Charlie Card (Boston)

I'm planning a trip to Boston, and I;m thinking of getting a Charlie card (the local stored value farecard), as the fare differential between the Charliecard and the "Charlie Ticket" is substantial. In Washington, one can buy a Smartrip card (similar to a Charlie Card) for $2 plus whatever fare you want to store directly from the vending machines. From reading the MBTA website, it appears that you can't use the vending machines to buy the card, you have to go to a ticket booth at the station. However, the website is unclear about the cost for the card over and above whatever fare you load on. How does it work?

I ordered a Charlie card from home and had it delivered to home. There was no cost for the card or the delivery. Sweet!

Home is in the mid-west. I don't recall if I ordered it using a web page, a phone call, or a paper form sent by USPS.

At the ticket counter last year the attendant handed me a card at no cost.

Cards are free. It's really unclear where to get them, I got mine from a roving customer service person by the TVM's at South Station.

If all else fails and you're sufficiently tall, reach up and feel around on top of the vending machines. I've found discarded cards up there, deposited by people who don't need them anymore. The good news is that you may luck out and pick up a card with a balance. The bad news is that your hand will be covered in dust.