I like to stick with acropora also. There are so many out there it is very hard to name them all. A lot of names may not be right either. If I have to guess though I'd say Tenius or samoensis because it looks thick, blunt, and very close polyps. That is a small frag though so it may change dramatically when it grows out some. You really need to be a focused marine biologist studying SPS to have a decent idea of what most of these are, as a lot of species look very simular.
At an rate, I'd buy it if you can pick it up for $30 or less. It looks like about a 1 inch frag.