Why does Eliza become angry with the apothecary?

Eliza is angry because the apothecary has increased prices for items used to fight the plague. He is robbing the sick and becoming rich at the expense of people's lives.

“The price of jalap and tea has climbed to the clouds since the fever struck. If he really cared, he would charge a decent price instead of robbing the sick. Pharmacists and coffin makers are the only people who profit from this plague.”