I'm looking at paying $9.50/20 for sapim db (14/15) spokes, and an extra $1.60/20 for nipples, plus shipping. Can I do better than that? And if so, where?

oddsand endos could be better depending on how many spokes you need.

That's not that bad. I don't think you're going to be able to save more than a candy bar's worth of $ unless you are buying by the 100/gross.

Yeah, LBS. even if you have to pay a little more, you can get em and bring em back 30 minutes later if you've made a mistake on length. (better yet, go to a shop where they've got the Phil spoke cutter!)