In recent years, Nintendo has had great success re-selling their old games in the form of the plug-and-play NES Classic and SNES Classic. Sony saw that success and wanted a piece of the pie themselves, so they launched the PlayStation Classic just in time for the lucrative holiday 2018 season. Unfortunately for Sony, it appears their latest piece of hardware was not stuffed in many stockings over the holidays.
The NES and SNES Classic consoles were sold out nearly all the time when they initially launched, but the PlayStation Classic could not achieve similar results. It launched to lackluster reviews and fans were lukewarm on the list of included games, and that all translated into a flop. Exact sales figures haven't been released (and may never be), but as a result of poor sales, retailers like Amazon, Walmart, GameStop, and Best Buy have all dropped its price for $100 to $60 just one day after Christmas.