Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Can I get a discount on merchandise by paying with cash instead of credit?
Slightly off topic... Not merchandise, but I paid for various doctor's appointments with cash (as opposed to paying with health insurance).  I'd call ahead of time and notify them that I'd be paying in cash.  I got ridiculous discounts, sometimes even less than the copay.  I do not know why this discrepancy exists and I didn't want to ask for fear of messing up a good thing.