I consider myself a Good Communist. Of course, what I consider to be Good Communism differs from what many others consider to be Good Communism or Good Socialism. That's OK with me: I think we need more rather than less diversity of opinion. I'm entirely uninterested in accusations of heterodoxy; you have to assert I'm actually mistaken to get my attention.
My self-identification notwithstanding, I think it's important to study specifically capitalist economics, and study capitalist economics on its own terms. Thus I'm actually going to college to study economics and political science (with a fair helping of mathematics and history on the side). I also read Paul Krugman, Brad DeLong, Maxine Udall, Mark Thoma, and a few other progressive capitalist economists. (I don't bother to read the Austrian, Libertarian, "freshwater" and Republican economists: in my not-at-all humble opinion they have their heads way too far up their asses to be at all informative or enlightening.) Yes, I share IOZ's opinion that progressive capitalist economists such as Krugman have a "radicalism ... rooted like a sidewalk weed, that is to say: shallowly," who "can't quite release [their] tenacious hold on the managerial vocabulary of a late-20th-century technocrat." But I don't read these economists at all to gain insight into communism or radicalism, so I'm untroubled by their politics.
If Marx is correct (and I think he is on this point) then any new political/economic system will inherit the preceding system. If we do get a communist society, even by revolutionary means, we will inherit the capitalist system. I'm studying capitalist economics as a communist because I think it's important to understand as best we can what we will inherit.
Furthermore, the capitalist class (and, if I'm correct, the professional/managerial class) have been running the world for about 200 years. While I'm not exactly popping a boner about their competence or humanity, I think one has to admire some of the achievements of capitalism, not the least of which are feeding and housing some six billion people and creating some very impressive technology. And they have accomplished this without micromanaging economic or political affairs. I think it's important that any future communist society not sacrifice these achievements, but rather surpass them. If you intend to surpass another's achievement, I firmly believe it behooves you to deeply understand precisely how they did it.
Third, it's an enormously powerful critique against capitalism that capitalists themselves actually know how to run a capitalist society much better than they're presently running it. If they cannot even apply the knowledge they have in the paradigm they accept, they are truly headed for the "dustbin of history".