The Boye needlemaster set of interchangeable needles?? Before getting that, do look into the KnitPicks Options or Harmonies interchangeables. They're cheaper and IMHO a much better set. (dd has the Boye, that we got on clearance, and they're fine for her, but after using the KP ones, I really don't like to go with the Boye.
You might do a search here for previous threads comparing the various sets of interchangeables. There was once a sticky thread, but I can't find it any more--lots of information around the site, though. The search feature is up top on the right of your page.