Expensive oscilloscopes can be a barrier for high school students, but alternatives exist for signal measurement. Using a computer's sound card can work for low-frequency signals, supported by free software that simulates an oscilloscope. The Raspberry Pi offers a budget-friendly option with oscilloscope packages available for under $300. USB oscilloscopes are also viable for basic measurements, though they may lack portability and bandwidth compared to traditional oscilloscopes. Overall, any oscilloscope is better than none, and exploring options like antenna analyzers can also be beneficial for specific projects.