Not sure I understand exactly what you're saying.

Welcome to the forum! If you bought credits enough to buy one card as a trial of the software, that will gain you entry to most areas of the forum. 50 Euros will buy 500 credits. At your entry level, each card costs 25 credits. When you have bought more cards, a sliding scale of discount is introduced, starting at Silver level... 10%. At my level, Double Diamond, my cards now cost me 15 credits.

So if you like what you see, just keep buying, eventually, the cards become cheaper to own :)