It depends what type of bluetooth you want, for example, stereo headset or mono headset?
I'm also looking at bt headset, provide you some price reference.
Stereo (which means support listen music/voice )
iTech S38 - support A2DP $340
iTech R35 - support A2DP and AVRCP (AVRCP - support remote function like forward/backward )$$$???
Mono (which means only support voice)
iTech Clip V - $320.