I am also a nursing student so I know what your are currently going through. This forum is the best that I know of, so you have def come to the right place. I own knockoff brand of the sprague, and they are good stethoscopes for the money. You can't beat the classics. Look around your clinical sites (if in clinicals, or go to hospitals and watch the nurses there) and see what the actual nurses are using, and not just the other students. I use a knockoff Littmann (ADC) and it works just as well as, if not better than the Littmann that I own. I also own a Littmann Cardiology 3 stethoscope because I wanted to hear everything best the first time around, and not have to guess at anything. For what you do in school, go with the best for your money. Ask some other students if you can try theirs out and ask the RN's or LPN's if you can try theirs out. Everyone likes something different. I work with RN's who use the cheap, cheap, cheapo $3 single head scopes, as well as RN's who use the most expensive Littmann Master Cardiology
stethoscope. Everyone likes something different, but just make sure you know how to auscultate heart, lung, and bowel sounds, and you can also get a BP and apical pulse. If you can do those effectively with your scope, then its good. Make sure you listen on many different people (10+) to make sure you can do all those things listed above on each of them. I found out my expensive scope sounds the same as my cheapo $3 scope on my body, so that is why try them on many different people.
Good luck in your decision and throughout your nursing career.