With availability varying by ZIP code, Amazon offers Prime members its Amazon Key Home Kit Service from $165 with free shipping. That's $5 under April's starting price, at least $125 off, and the lowest price we've seen. You'll be sent the Amazon Cloud Cam Indoor Security Camera (which features 1080p resolution, two-way audio, and compatibility with Alexa) and an Amazon Key-compatible smart lock of your choice.

In Amazon's words: "As a Prime member, you can choose to get Amazon packages securely delivered just inside your front door. Watch your delivery happening live or view a video clip of it later. We'll send notifications the morning of delivery, just before, and right after. Or choose to block in-home delivery." Of course, it can also be used for home monitoring as well.

Note: This service is not available in all areas at this time.