BigDeals via eBay offers the open-box Philips In.Sight Wireless Home Monitor for iPhone/iPad/Android, model no. M100/37, for $49.99 with free shipping. That's $10 below our March mention and the lowest price we've seen for this monitor. (It's also the lowest total price we could find today by $19.) It features a magnetic base, expandability up to 16 monitors, 802.11n wireless, operation via iPhone and iPad app, noise and motion detection, and the ability to upload recordings to Dropbox.
A 60-day BigDeals warranty applies.