That's right, Aluminium is 50% lighter than steel, but Titanium is only 40% lighter. However, even when specially alloyed with other metals and heat treated, Aluminium has only only 50% the strength of steel, whereas Titanium easily matches steel for strength. Accidentally drop an Aluminium pot onto a hard surface, like onto a tarmac road, and it will either dent it or it will have noticeable scratches. Do the same with a Titanium pot and there probably won't be a single mark on it. I found this out first hand! Unlike Aluminium, Titanium is completely non-toxic, and far more corrosion resistant too, plus it doesn't hold heat for very long, so you are less likely to get accidentally burned when using Ti pots. So yes, Titanium may be more expensive, but it's worth every penny!