Its an nice card, but it looks scary to me in the way it is now worded. Lets make an example:
You start with Quarry = 4 and play this card:
Your Quarry is greater than 2, so you gain 30 tower and you loose 2 Quarry.
Now your Quarry is equal to 2, the next condition is met and you gain 20 tower for 1 Quarry.
Now the last condition is met and you gain 10 tower, a total of 60 tower for 3 quarry got the cost of nothing.
In a lucky starting hand (Like Minaret+ Master bricklayer +this card) You can win a normal game with construction within 3 rounds. I would appreciate this, but its kinda imbalanced and i think this is not the idea of this card.
I would just connect the other conditions with an else:
If quarry >2
quarry: -2
Tower: +30
else: If quarry =2
quarry: -1
Tower: +20
else:
Tower: +10
(The last Condition is redudant)