in a reply to what has been said about balance, isn't the very purpose (and definition) of an upgrade to make the card better? most cards when upgraded lets say for example, precognition, becomes unbalanced. it is balanced when unupgraded, costing 2 quanta to see the opponents hand and draw, and the it draws you another card. but then you pay 1.5k and it suddenly halves it's cost and retains it's ability. upgrade is basically changing the balance scales and puffer fish certainly does not conform to that. it stays balanced like a normal card.