It's from earlier this decade, and I think that it's the one that they made in the first half of 2014, according to the tech support guys who sold it to me. There have been a few major discounts coming from their office, selling used Macbooks for a couple hundred dollars and stuff like that. Not just anybody can buy them.
In any case, the takeaway here is that I have a Mac. Specifically, a five-and-a-half-year-old Mac Mini, with some dismal I/O and a little bit of dust inside. However, it was only $50, and when I looked up Macs from when this model was first made in 2012 (this was made in 2014, but it didn't refresh the 2012 design; also, it looks like someone expanded the memory on it), the price of refurbished 7-year-old Mac Minis is nine times as much as what I paid. So I got a pretty good deal.
Not that I'm using it. I'm giving it as a gift to a friend whose old computer broke down, and I'll let him assume that I paid the standard refurbished price for it, somewhere around $500. If he wants to pay for my next few meals, then my purchase paid for itself.