You want HOW MUCH for that card?
As a trader of playing cards I get that 'question' a lot. People are sometimes very suprised when I tell them how much some cards cost.
Let's get one thing straight - I don't make the prices for the cards.
So, how is a card valued? Easy - it's worth as much as someone is willing to pay. So that leads us to our next question, 'why would someone pay that amount?' - well, the answer to that is a lot harder; but I'll try :)
The greatest thing about Australia is our commercialist society. If you have an item that is in high demand then you are entitled to raise the price! Yet an Auction is the only place you can get a TRUE value of an item, a shop is only putting prices on items that they perceive it is worth - if you never sell the item then it was never worth that much.
Ebay is the largest Auction site in the world which means you can always get a good idea of how much a card is worth. In fact for my specialty (Magic the Gathering) I subscribe to a monthly newsletter that tells me how much each card sold for in the previous month; all 17,500 cards!
So lets explore some reasons why some cards are in demand and others aren't.
There are a lot of reasons why a card is wanted; the most obvious reason is it's playability. 'Magic the Gathering' is a fun game and the majority of people play it for that reason; but they also like to have a competitive deck! Those people will track down which cards they beleive will boost their decks and then buy them (or Auction them), and with (approximately) 30,000 customers on ebay wanting 'Magic the Gathering' cards prices will be pushed up for the better cards.
EXAMPLE - Black Lotus is now worth US$1,400.
I'll admit it, I started playing Magic in 1995 purely because of the artwork. There are people out there that don't play the game yet collect all their favorite pieces of Art.
EXAMPLE - Dragons! It doesn't matter how bad the playability of the card is there will always be a buyer, I can't keep them in stock! Rebecca Guay is an artist that is always in demand.
When I first started this game the first card that ever made me go 'WOW' was 'Howling Mine' (Revised edition). My first words, when I saw it, were 'you can do this??' and my 3 opponents laughed.
This moment has stayed with me and the card has a special meaning for me, whenever I see a Howling Mine (any edition) I always remember the day I first saw it and laugh.
The first set I ever completed was 'Homelands' and the 'Baron Sengir' card is special to me, I have about 8 copies of it (I have even turned one into a fridge magnet and another into a sticker!). If one comes up on ebay then I will bid on it.
I have sold a lot of cards on ebay and over the Internet over the years, and in that time I've seen a lot of card price fluctuations. Cards that people were thought were good turned out to be not-so-good, cards that were thought to be bad turned out to be able to win games when used in certain combinations.
On several occasions I've seen cards that sold for a lot more than what I thought they were worth while others have sat in my store for over a year.