But my problem is that I see cheap ($6ish) BT modules on ebay, but can't seem to find anything from a repeatable online vendor like Digikey or Farnell for anything near that price range. Ebay's great for one-offs, but if I ever have to build 200 of something, I'd like to avoid it.
Mouser have some BT modules that may suit your needs but your talking $15-$20+ each.This
company looks like it can sell in large quantities at $8.76 per unit in 100+ numbers.This
lot also look like they may do large numbers at $4.20 per unit or less.