, my priority is the basic necessities based on my capacity, and when there's excess, I buy budget-friendly items. If you're poor and you overspend, you will have big issues with your budget.
The ops description of poor and rich is literally unclear. You can't classify someone poor because he bought something expensive or rich because he didn't. All of these are mindsets. If you are able to provide your basic needs and sustain yourself in a struggling economy, why then do you think you are poor? The poor barly have time to think about buying something, talk less of an expensive one. What we should focus here is how the average folks would get able to minimise their spending and cover up there expenses.
I guess "poor" here is the one who can't buy something more than he can already get based on his income. He will need a big effort to buy something over his budget and/ or sacrifice other needs. Meanwhile, the "poor", as you said, are the ones who can't afford the basics. So a poor wouldn't even think to buy something no matter the price of it.
As for the average person, minimizing their spending depends a lot on how he thinks, what priorities he has, and what's his goal. Expenses and their volume come afterward.