IMO, buy from reputable spareparts shop / shopping mall..
change oil regularly if you love your car, fully synthetic 7k interval or 3 months..

you wanna buy cheap and you want the oil as good and smell/taste the same like the original one? doesnt work like this bro.

one mech told me that whatever the oil is, as long as it doesnt slime after few km's it will be ok, just like cooking oil.