cooking oil

I asked my son to pass by supermarket to buy cooking oil, that in plastic bottle. I told him to choose the ordinary with omega 3 oil. That cost 120 pesos for 800ml. My son said "Mama why don't you buy the Olive Oil? That's the best oil and therapeutic unlike the ordinary cooking oil causes so many kinds of heart diseases". My son thought that olive oil is the same price with ordinary oil. If i have not mistaken 250 ml of Extra Virgin Olive Oil in the supermarket cost almost 300 pesos. This is too expensive for me and i am using oil almost everytime i cook food. It is out of my budget.