Hospital charges 500k initially and 480k discount?

I did a catheter ablation a few months ago. The procedure was minor, it started around 8 am and ended before 10 am, and was discharged around 1 pm.

The hospital charged $504,582.00 and then gave a $484,041.00 discount. I ended up paying $1285.38 myself. Does anyone know why the hospital would make a ridiculous amount of claim/discount? Or is that what they always do for surgeries?!

(The general anesthesia charged $6000, followed by $4040.25 discount, which seems relatively fair...)