BrandsMart USA offers the Uniden U-Bell WiFi Video Doorbell for $39.88 plus $4.99 for shipping. (You may need to search for "DB1" to find it.) That's $35 under last month's mention and the lowest price we've seen. (It's the best price today by $35.) It features an alarm trigger, motion activation, 2-way audio, and night vision.
Before you spend another dollar on items and services like these, check with your public library. You will likely be surprised by what it offers for free.