Cafago offers the KKmoon 7" Wired Video Door Phone System Visual Intercom Doorbell for $67.79. Coupon code "ZS947MG" cuts that to $50.84. With free shipping, that's $49 off and the best price we could find. It features a 7" 800x480 LCD display with infrared night vision, built-in light sensor, and 16 ringtones.
Note: This item ships from China and may take two to five weeks to arrive. Also, the countdown timer on the product page does not reflect an actual expiration time and resets daily.