To balance cost and durability, look for ABS plastic housing with a matte finish, as it is impact-resistant and hides scratches better than glossy finishes. Ensure the speaker driver diaphragm is made of high-quality composite paper or silk for better resonance. For portable units, verify the IPX rating (e.g., IPX4 or IPX5) to ensure basic water resistance, which adds significant market value to 'cheap' electronics. Check that all soldering points on the PCB are clean to prevent short circuits during long-term use.