Amazon has the ANNKE HD 1080p Wireless Wi-Fi Camera for only $89.99 (Reg $199.99) with Prime Shipping. It features 2-way audio, a 2.0MP sensor and infrared motion detector.
If you are not already a Prime Member you can join with a 30-day free trial of Prime, as a student with Prime Student, or as part of Amazon Family.
Please note that Amazon prices are subject to change at any time and may have increased or decreased since this offer was posted.