Where do you buy magic cards? And how much do they cost?

I'll sell you some for $1000 a piece. If you plant them they will grow into magic beanstalks.

There are a number of businesses, both storefront and on line, that cater to stage magicians. There's quite a range in what they offer: some cater primarily to amateurs and also sell other "jokes" and novelties, some cater to the professional and carry or produce only stage-quality mechandise.

If you don't have a magic supply store in your area (look in the yellow pages under "magic"), you can find one on line by going to google.com and entering:

"stage magic" supplies

(You want to enter it that way, with the quotes around "stage magic," to avoid getting sites about other kinds of "magic" such as the Magic the Gathering collectible card game, or "occult" magic shops.)

You'll find a variety of card tricks and decks available for a variety of prices, ranging from fairly inexpensive to pricey.

However, many of the best card "ticks" or illusions are performed with a regular deck. The "magic" isn't in the cards, but in the perfomer's knowledge of manipulating them, ability to misdirect attention, and sleight of hand. Even if you purchase a special deck or card trick, being able to perform it successfully will depend on your ability more than on the cards.

So if you want to learn card tricks, you might start by picking up one of the many books available on the subject and a regular deck of cards instead of any kind of specialty item.

You can get some cool magic decks at the dollar store

Best way to buy Magic Cards for cheap is online, and I find the best place is MTGFanatic:
http://www.mtgfanatic.com/?ForumReferrerID=127300
They have lots of promos and a point reward system which allows you to get discounts or even free cards. You can get commons for as low as .08¢ where as most others charge you .15¢. They are fast and have good shipping rates. Cards vary based of supply and demand. Ergo, cards that are older and not printed as much and and are really good can be from $5.00-$20.00. While extremely rare cards can be upwards to a couple hundred dollars. While most cards vary from .25¢-$6.00