You are actually able to buy more than one card per turn if you play the Merchant boats card. One more card per each Merchant boats. So then you would be able to buy more cards provided you have the money. Thanks for the feedback and for playing our game.
Thank you for the feedback. The shop not being brought up between turns is actually a feature implemented in order to limit the maximum amount of cards in the player's hand to 5. I definitely agree that it should be communicated better though.