Very interesting, I guess this explains the low prices of some of these cards at the current market and that they will probably increase steadily through time? Being quite new to Splinterlands, I was surprised to see that some of these cards like e.g. the green Djin or exploding rats are undervalued, despite clear utility with some rulesets.
Mammuter
Yes, while cards are being printed/are available the prices tends to be lower. When the cards are out of supply the prices tend to steadily grow. That's why older reward cards which seem to be less useful are higher priced. Another factor to take into account is the number of cards which are printed. New Reward cards are printed in a (much) higher volume than previous cards. More supply, lower price.