i have a motorola h550. I got it from office max, after the mail in rebate it was about $10.00. That was awhile ago but it is decent. I dont use it much, in the car I use a motorola t505 and love it.
I have found had I just spent the money on a good one the first time, a lot of money would had been saved. Not all BT devices work well with the BB. I have a Jawbone icon and it has been the best so far. It is more costly, but it is the best.