Star Realms is a deck building game. That means you start with a deck of 10 cards of which 8 (Scouts) do nothing but provide 1 Trade to buy more cards from the trade row. Unlike deck building games you might be familiar with such as Dominion or Aeon's End, the market isn't static. Instead, the Trade Row is populated by 5 random cards drawn from an 80-card Trade Deck.1 Each of those cards cost from 1 to 8 trade and is replaced by another random card when purchased. Since you draw 5 cards,2 you'll need to buy cards that will, in turn, provide more trade later on to buy more expensive cards. A reasonable strategy is to simply buy the most expensive cards you can afford in your turn.
This is a companion discussion topic for the original entry at https://jlericson.com/2022/12/30/star_realms.html