I don’t see that. If there is any difference in cooking time it is a minute or two at most and that much energy is not going to cost you the difference in price. It is very hard to make any assumptions about pasta cooking time as the thickness is not standard, your nominal spaghetti (or any other shape) may vary in diameter from one brand to another regardless of price or name.
What could that possibly be? I think if they add sawdust it has to be listed 
.None that I can see list any ingredient other than durum wheat. The content is very much the same in protein, energy and carbohydrate. Different brands do have different amounts of salt but the cook should always deal with that as they do for variations in cooking time.
