You're not going to get much in the way of a 5.1 for $50.
Double your spending limit and you can get this for 79.99 + tax.
Logitech® X530 5.1 70W Speaker System (970114-0403)
• Five satellite speakers
• High-tech subwoofer
• Wall-mountable
• Patented technology
Immerse yourself in sound: Plug this system into your PC, music player, DVD player or even your PlayStation® or Xbox® game console. The matching front and rear satellites deliver balanced surround sound, and the dedicated center channel makes dialogue clear and intelligible. The clean, crisp, consistent sound will bring your music, movies and games to life.
Patented sound technology: The high-tech subwoofer adjusts itself dynamically to deliver distortion-free bass. The five wall-mountable satellite speakers use patented FDD2™ technology to eliminate the uneven sound response created by conventional dual-driver designs. The result is a clear, uniform sound field without the inconsistency of other dual-driver satellites.
Easy to place: The satellite speaker stands rotate for easy wall mounting or desk placement.
Note: Connecting to PlayStation®, Xbox®, or DVD players requires an adapter (sold separately).