Stock Thunderblast vs Detachable Missile launcher

I'm going off to school, so I'm going to start selling a few things. Before I do I wanted an opinion:

I have a new-in-package thunderblast and a recon barrel extension. Would it be a better idea to sell them separately, or as one? (Meaning I chop off the back of the thunderblast and integrate just the front part as a detachable missle launcher.)

Would you rather buy this for cheaper:
Image may be NSFW.
Clik here to view.

Or this for a little more?
Image may be NSFW.
Clik here to view.