interconnect vs speaker cable

Everything being equal, and I use that term loosely, of course; which one, interconnect or cable, gives you the most sound for the dollar? How about this way? Again, things being equal, which would you upgrade first, or better yet, if you could only upgrade one, due to $ (and you couldn't make the other upgrade for a long while), which would it be? I know, I know, there are loads of other factors, but just let's pretend there aren't any, or, again, everything's equal. There's that ubiquitous "equal" again. Thanks in advance.
warren