Is it just me, or did it seem as if Whedon brought back the Internet millionaire guy (Joel) to bookend the show's ongoing exploration of how the Dollhouse is morally ambiguous and while it ends up performing questionable and sleezy services, it actually does do the right thing at other times? Everybody (the viewers) responded well to Joel in season 1 and folks considered that a turning point episode. Also notice that Alpha succeeds in murdering all of Echo's "dons" who were just using her, as Alpha says, for a little piece of her. But Joel, the one person who truly, deeply needed the Dollhouse service to help himself heal, is shown to have gotten better and moved on.
Amid the Whedonesque hard edged nastiness, that's actually a very sentimental resolution to the storyline.
... on the other hand "Who doesn't love a pun?" is one of the best lines ever in context.
I think in his case, Alpha didn't really care, or really care about any
of them. The others were to draw out Paul and Caroline, but mostly Paul because he had been spying on them for the three months they were on the run. It might also help, that given the nature of what Joel did, renting Echo to see the expression he never got to see, and that it was to see Rebecca and not Echo, Alpha saw it as a different type of engagement. Joel also seemed to truly care for Echo, not because of what she can provide, but because she is a person, and that she allowed him to ultimatly find a new happiness and move on.