Please understand that this is the thinking of literally everyone I know without exception who survived (or didn't survive) a serious opiate addiction. You will come across dealers or find other ways to acquire it. You will probably not get addicted this month but life circumstances and the basic biochemistry of opiates will alter your priorities of what you can afford really quickly.
I speak from not just the experience of everyone around me, but personal experience. And just read through the archives of this site. I have seen the same posts over and over, and then a year or 2 later the OP is back lambasting him or herself for being naive. Or worse, they end up in the Shrine.
It's worse now than even 3 or 4 years ago. Fentanyl used to be used to step on H occasionally and you'd have a report of a bad batch in NJ or NY or whatever every few months. Now it seems that not only is most of the supply of east coast heroin cut with fentanyl analogues, often they are just fentanyl. Even forms like carfentanil that were previously only used on large exotic animals or as chemical warfare agents (see Moscow Theater Crisis). Yeah, that stuff is at least confirmed to be all over Ohio and it's slightly over 10,000 times more powerful than morphine.
You can prevent an opiate addiction only when you accept that there is no such thing as long-term occasional use for at least 9 out of 10 people. That cloud of comfort is the artificial triggering of the same endogenous reward pathways that cause any form of satisfaction, joy, accomplishment and drive in humans. I don't like preaching and I'm a hypocrite in a sense, but I'm just so weary of seeing this.