Those are a very expensive option, i was thinking you meant a titanium coated bolt.
I have a set of wheels for my trackday alfa that are around a kilo lighter than some other wheels i have and i can tell a difference in steering, it's all about the unsprung weight, i have also fitted a stud kit and very light alloy nuts to make a difference but the costs involved in that were only about £80
£500 is a bit different.