Seems like the best price (so far) on this wireless camera system. Not sure how good the system is, but the specifications look decent.
100% Wire Free Installation
Year Long 365 Day* Battery Life
Full HD 1080P Waterproof (IP66) Camera with Night Vision
Free Local Storage, No Monthly Fees
Supports Amazon Alexa, Google Assistant & IFTTT
Edit: In case anyone was wondering, additional cameras can be purchased ($299 each or $239 with TGG eBay deal) and added to existing base station. A maximum of 16 cameras can be added to a single base station.