Stethescopes can run from the cheapo $7.00 one up to several hundred dollars, and it doen't matter if it is a Littman, Sprague, or any other brand. My most expensive one was a Tycos triple header--- which developed legs and walked off the last week of June many years ago and hasn't been seen anywhere since.
You said this one had 5 heads; what did your friends' uncle do? I can figure out why there would be up to 4 different interchanngable heads for a stethescope (peds and adult sized bells and diaphragms) but what on earth would the 5th head be for? My Tycos actually had 3 heads on the chest piece, so I had an adult diaphragm on at all times and an adult and peds bell. It made it easier to hear friction rubs and murmurs, especially on skinny elderly patients with mitral valve problems.
Try several stethescopes out on heart and lung sounds in a lot of different settings-- even try it on kids in a car if at all possible. BPs aren't the thing for honing listening skills; you are just interested in hearing the Korotkoff sounds then. Remember, you can bend ear piece tubing slightly if you ears aren't even. And there are several types of ear pieces- find some that are comfortable for YOU. I've traded ear pieces with co-workers because of opposite personal preferences- I like one style, she likes the other.
Remember, your stethescope is an instrument you will (hopefully) be working with for years and making assessments with. Try several out and find one that is a good fit for you--- then brand it so no one else will ever walk off with it!!!!!