Ciao Sergio!I think you would like to see the point of view of someone who only collects cards and doesn't play the game
The basic point that makes a card/object precious to a collector is the small number of copies the card/object exists.Yes,no doubt,there are a lot of collectors who are specifically interested in cards with alternative artwork,but who would pay more than $0.50 maybe,if they were just commons
And who would trade his/her Italian Assasin for a Dutch Lure Of Nature with alternative Daelomin artwork,although he/she has the Assasin doublicated and collects only alternative-art cards
So the prices or trade values for such cards are decided always having in mind how RARE is the card/object AND the "bonuses" it has(for example alternative artwork,artist signature,production-mistake-misprint,card condition etc.).
Now you still wonder who may pay such a price(or trade so hard...)???Just think that DO EXIST people who would give one of their eyes,to admir an Ansient Greek statue in their collection with the eye left
(and ofcourse their willingness to pay comes to millions of dollars
).A collector has only "Willingness To Get",not "Willingness To Pay".A collector may pay as much as he/she CAN AFFORD to get the precious object.Traders/sellers understand that,and a price/value is given to the card/object,so that the most hard-core collectors can afford it.This way,they get the highest price possible.
These prices serve collectors very well,although they have to pay more.How this happens
Well,imagine yourself looking like a mad for a Japanese Fury Of The Iron Crown,finally one copy appears on a sale/trade page and the price is $10.The card disappears as fast as it appeared,and you look the card in the hands of a gamer who uses it in a game,suffles it in the play deck destroying it,and when you ask him/her WHY
,he/she says "I like to see opponent's face when I play THIS card!!!"
Ok,so he/she is just a posser who took your precious "Fury" for $10 and destroyed it's Mint condition,while you would pay up to $100!!!
Do not compare a bidding with buying a card with a fixed price.I said collector will to pay a lot,but knows how to consider competition between bidders and will pay a lot IF NEEDED,not anyway
What I'm trying to tell you is that a rare object will be unavaillable if it's not expensive.So,you'd better check multiple traders/sellers when you want a card.That's the only way to FIND the card first(Which is the most important...)and choose the best price
I guess trading for card you want would be worse for you than buying it,if you don't have a card that your partener-trader REEEALLY wants or he/she could sell it for a better price than the card you want to get...You may have 3xOne Ring English Lim to trade,but you wouldn't get a Ramaviva for all 3 of them,possibly