Medical pricing is so hopelessly complicated that few doctors can even tell you what a procedure at they perform themselves at their own hospital will cost you. I don’t know how they could keep up with pricing for thousands of drugs interacting with formularies across hundreds of insurance plans.
At least on the Rx side, it's really not that hard to have a general idea. Youre prescribing mostly the same medication over and over and patients give feedback, so knowing a general discount card price isn't difficult.
If the patient has a weird formulary or a high deductible, that's on them to understand.