Titanium is well known for its high strength to weight ratio and you can buy only the quantity you need. If you only lost a stake or two, you don't need to buy a whole bunch of new ones. Tite-lite(tm) stakes have nice gentle points on them, so they don't puncture your lightweight pack.
For the Spinnshelter, we recommend a minimum of 8, which gives you a stake at each of four corners, two guy lines, and two vestibule stakeouts. You may want to consider getting 12, which gives you extra stakes for fastening additional stakeouts. This allows the use of all five stakeouts on the windward side of the tarp.
Lightweight and strong
Gentle pointed tips are easy on your lightweight pack
Sexy titanium hue (grey)
Priced per unit, select the number you need
0.22 oz /6g.