The Playstation TV is a remote console that can be used to play PS Vita, PS1, and PSP games, as well as remote play with the Playstation 4 and on Playstation Now. And right now you can get one for about $20 from the Sony Store. The Playstation TV is meant to be something of a portable way to play PS titles, being very small (in both physical size and the amount of data it can hold) and easy to hook up. Because of that it's been given away for free in the past with purchases of a new Playstation 4. This is the cheapest it has even been sold individually, at a pretty significant discount at that. It seems that Sony is attempting to give the mini-console away, which hasn't been very well received for a number of reasons. Among those is the fact that the Playstation TV doesn't hold much in terms of data, having only 1GB of internal data to its name. To get more, you have to shell out money for a PS Vita card, which are enormously expensive. The discount is tempting until you find out you'll be spending that on a new memory card just for the system. The system has been sold at fluctuating prices, marked to be sold at $100 though rarely actually sold at that price. This is the lowest it has ever been sold individually.
The Playstation TV also doesn't come with a controller, though it was intended to be a supplement for the Playstation 4, so it's likely assumed players already have one. You can however save a bit by getting the bundle, which comes with a Dualshock 3 controller, 8GB memory card, and The Lego Movie Videogame, on top of the system, for about $40. It's worth noting that, at the very least, this is about the price of a brand new Dualshock 3 controller alone, so it may be worth the price at this point. Keeping in mind its limitations, the Playstation TV at $20 (or the bundle for that matter) is probably a good deal. At the very least if you're looking to get a PS Vita and don't care as much about it being a mobile console, this is a cheap alternative (keeping in mind, not all PS Vita games are compatible).