B-movies are sometimes envisaged as an inferior kind of films. No, it means that the production costs are not as elevated as A-movies. If a star actor gets, say, 1 million dollars for a movie, well, some films (without stars) were made with an overall expenditure of less than 1 million. Now, I don't really care about production's costs, and some B-movies are better than the more high-class ones (not this one, I must say).
The strong positive values of "The Pusher", in my opinion, are the well-defined plot, without any confusing sub-plots or blurred images and shots that let you quite uncertain about what has really happened, and the consequent linear execution of it. This is also a detrimental point, because when you reach minute 16th (of the overall 82), you will know exactly how will the narrative develop.
No thrills, consequently, but if you are a lover of the genre you will enjoy this film. I rated it 6; let's say, more precisely, 6 and a half.