Depends on how much of a stickler you are about FOC... 10% should be a bare miminum, and I'd prefer closer to 15%;a lot of guys are going with 20% these days.

I actually ordered the brass inserts with lighted nocks in mind, thinking I was going to purchase either Easton's Tracers or Dorji's Firenocks. But when this guy at Bass Pro showed me how slick the little battery was (even though I'd seen that video several times before...) and I was able to hold it in my hand, I could just envision how easy it would be to build them.

We'll see... Like I was telling Bob (Gr8) earlier, I may play with these for a while and realize that it's better to buy the factory ones, and then I'll know. But it'll be one more aspect of bowhunting that I'll have first-hand experience in and can talk knowledgeably about.