What are you doing with this oil?
You can't saute anything in flaxseed oil because it will burn. YOu have to add that to food that is already prepared.
You can't use unrefined olive oil at high temperatures (you should be getting extra-virgin oil).
I wouldn't just buy "vegetable oil" because it's more likely to be more polyunsaturated than more monounsaturated (like olive oil). But this kind of oil is better than the others for deep frying. Canola is best for high temperatures.
I keep extra-virgin olive oil and (organic, cold-pressed) canola oil in the house. Olive oil for salad dressings and sauteeing vegetables, canola for cooking foods that I don't want to have the taste of olive oil.