If you don't have enough money, and can only barely afford to buy something, then yes, very much you will follow it religiously. You will try to buy the most reliable for the cheapest price, because you can't afford the product failing, nor can you afford paying too much, and you don't want to go back to getting food from the food bank so you can spend your grocery money to replace the broken washing machine.

Of course if you're a SV programmer earning 5-10 times the average wage, you don't care about this and buy overpriced shit every day, but many people follow this to the letter.