This is very correct because if you don't consider the profit that you're going to be making from the advertisement you want to invest on, it will simply be a complete waste of money on ads.You need to first of all, consider the kind of profits that you will likely get before you throw your money on ads. You want to make sure that it is actually profitable for you.
I wouldn't really know because I haven't started doing ads on Facebook yet. I don't have any business to promote on my Facebook but when I do, I'll find out.Do you believe in spending huge money on Facebook ads? What guides you while deciding the budget?