The amount of time I have spent trying to track one down for purchase is ridiculous. Only used ones on ebay and Amazon. No trouble getting an extra camera, but when it comes to the entire unit - dead end.
I have found similar units but they are often $100-200 more. Extra quality not needed for this application. BTW, I'm an expert on baby monitors now!
Walmart and Lowes in the US seem to regularly stock them. Lowes price is higher. Found a couple of distributors, but they don't ship to Canada.
The vast majority of reviews I have found are positive. At one point I thought they may be going out of production, but I don't think so. Seems that they have only been available for about 2 years.