The fourth boss is impossible. One does massive damage, and the other keeps healing. So when you try to stop it from healing, the one with massive damage takes you down
Getting money isn't that hard. I got over 1k in about 2 hours. First you need to unlock Nightmare mode. Thats hard work, but with many tries, you can do it! Just go to Nightmare mode, die once, change difficulty to easy, and you get the same amount of money you would get from nightmare, except its on easy.
@legendaryhero12 If you read the description carefully, it said you would have a CHANCE of getting the pet. It will take you 5-10 eggs to hatch one, so don't feel unlucky.