What biblical verses or Christian sentiments support price gouging as being unethical or ethical?

I’m having a couple arguments on Facebook with someone who is twisting my words. He is a free enterprise, no government guy, and he is be a pain in my neck also about politicians using their Christianity to market themselves for elections. I also am a free enterprise person, but only to a point. When a price is gouging, taking advantage of people, or causes such a huge profit that the company could easily charge less and still make billions, I believe it often hurts our country and our economy in the long run creating big bubbles and bursts.

It made me wonder what specifically in Christianity might demonstrate why price gouging (we got off on a tangent about pharmaceutical prices) is not Christian, and if America was founded on Christian principals then taking advantage of the sick is incongruous to that philosophy.

Thanks.