As you get into magic, like most things, there are many lessons to be learned. Who amongst does not have a small drawer or pile of "tricks" that you purchased that are basically junk? I know I do...
As you learn the art of magic, using books and carefully reading and understanding what people on this forum and anyone else that can teach you from what they already have learned, will save you lots of time and money. As noted above, purchasing a 'trick' is a real risk unless you have done your due diligence before purchasing.
One of the first things I had to learn was that the 'trick' is one a portion of a performance. Doing a trick perfectly will get little if any reaction from an audience, like hearing an actor read a line from a movie, by itself, it has little impact. You need to have a story to go with it, you need to have visual interest, and then you need to perform the trick perfectly....
I have read many times that to learn and become a Top Professional Artist, whether we are talking Oil Painting, Musician, Dancer, Singer, or Magician...it takes 10,000 hours.....I believe this to be true!