Firstly, I should start by stating that there are three grades of quality when it comes to these new Star Trek uniforms - Heritage, deluxe and... err... this one (I don't think it has a specific quality attached to it). As you may expect, the uniform itself is not an exact movie replica (like the expensive heritage uniform).
Here's some detail regarding the quality. The shirt itself is made of very thin man-made fabric and feels quite cheap. The neck (or dickie) is sewn into the uniform and is not a separate undershirt. The badge and rank braiding are a non-reflective rubbery transfer. The colour of the shirt also seems to be a little lighter than in the movie.
Also, as someone who usually buys small mens shirts, I found this medium shirt to be a little bit on the loose fitting side. You might want to keep that in mind if you are the same. All in all, pretty good for the price, though I would have been annoyed with the lack of quality had I bought the shirt at full price.