The quality of the visuals and the audio (more on that below) are clearly the most important performance criteria. For the most part, the video on inexpensive webcams passes muster with webcam reviews, experts and users alike.
Expert webcam reviews on CNET praise the clear video images on the low-cost Microsoft LifeCam VX-5000 (starting at $35) but criticize the choppy video at high resolutions and grainy video at low resolutions on the pricier Microsoft LifeCam VX-7000 (starting at $45). An expert webcam review of the Microsoft LifeCam VX-3000 (starting at $25) on PCMag.com says this entry-level model is OK for video chats although the video quality is mediocre.
Users posting webcam reviews on Best Buy like the adjustable lighting feature on the HP Deluxe Webcam (starting at $100), which nicely displays your face even in darker rooms. The Logitech C500 (starting at $41) likewise earns praise in webcams reviews on Amazon for its ability to adjust to dim lighting and on Best Buy for its ability to focus (one user notes it doesn't blur when there's movement in the background, like a puppy running helter-skelter).
The Creative Live Video IM Pro does an especially good job of focusing by tracking your eyes and nose and cropping your image accordingly, according to a webcams review on Buy.com. Its cousin, the Creative Live Cam Notebook Pro (starting at $31), relies on a manual focus, which users posting reviews of discount webcams on PCWorld.com say delivers decent visuals but note that good lighting helps.
The Ezonics EZCam II (starting at $15), on the other hand, takes hits in user webcams reviews on CNET for very poor image quality even in bright light. An expert webcams review of the Ezonics EZCam II on CNET is more pointed, noting that the stated resolution for this webcam is 640x480 but the highest useful resolution is only 352x288; at anything higher, the review continues, the webcam drops frames. The CNET review also says the Ezonics EZCam II's focus is poor, as is its ability to pick up detail.