This guide provides an estimate of the relative strength of each card in Heart of Crown PC!
It was originally written by garrodrive-sensei, top ranked player from the Japanese HoC PC community. The guide is divided into sections for each Cost in the game.

For Territory/Action cards of Cost 2~5, it's based on the value during Turn 1~2 of the game.
This is measured using an arbitrary unit called Card Power. A card with Card Power equal to or greater than its Cost is generally more powerful. Of course the actual worth of a card depends on the situation, but this is a good overview of the general value of cards for beginners.

• Cost 2, Card Power = 2.5
  If you have 2 Gold, prioritize this card. If you have 3 Gold, get a card with Card Power ≥ 3.0
  
  
• Cost 2, Card Power = 2.0
  A card worthy of a 2 Gold cost. If there are no other options, and it doesn’t interfere with your strategy, feel free to pick it up.
  
  
• Cost 2, Card Power < 2.0
  Even if you have 2 Gold, it’s probably better not to buy this unless you have a specific reason to.