There are already millions of Americans that started their opioid adventure with oxycodone or hydrocodone, often coming from the "upper spheres". Addiction does not discriminate. Changing the name from amphetamine to Adderal will not give you more control over your addiction. You will have none, regardless of your income level.
You are right about the safety level though, this is about potential short-term complications. Prescription stuff is not contaminated, a doctor can give you some good advice, or a vial of emergency Naloxone.
However, if you are not in such a good financial position, a heroin addiction will almost certainly ruin your life. From the financial burden of the substance itself, to side effects from adulterants and the impredictability of a dose, you roll the dice every time you shoot up.