There are a few options for bone conduction ear pieces in that price range that will perform decently. Now whether or not the price is worth it over a normal acoustic tube set up, that is up to you to decide. Personally I'm right on the edge of thinking it is and isn't worth it, I will say I like the technology and how they work but they are a little pricier.
Edit: oops, I forgot the link
http://www.cancomradioaccessories.co...tion+earpieces