I went through this same phase about 3 years ago. First e-cig I tried was from nJoy, before I even knew that there were better products. It was OK, but not enough to get me completely off cigarettes. After I discovered the eGo stuff, I never looked back. (Have since moved on to a Lavatube / Nova combo- that's the sweet spot for me.)
At no time along this whole path did I ever concern myself with "Gee, how can I continue to use this old, crappy thing which I decided to replace with something better?" You've heard of the concept of throwing good money after bad? Consider the Blu to have been an educational experience, toss the batteries into the recycling container at your local Best Buy, and the rest into either the trash or the municipal recycling stream.