Altho i'm loathe to use the word/admit it, i collect vinyl records. i tend to focus on a specific sub-genre of one that's not uber popular, so the records i'm really after and willing to spend more than list price on usually don't go for too much. Many of my peers are into collecting every variation of a record that's pressed on multiple colors of vinyl. (ie, a label will press 1000 of a particular band's album. 500 of these will be on black vinyl, 250 on red, 200 on green, and 50 on clear vinyl.) My collector nerd friends would then seek out all 4 versions. Indeed, a lot of labels even offer a pre-sale package featuring all 4 variants, particular for these guys.
In addition to a completist mentality behind wanting to own every variant of a record, there is also a demand (ranging from "mildly interested" to "i will mortgage the house to get this") for "test pressings" of records. These are just like what they sound. There are usually fewer than 20 of these made per release. Often less than 10 or even 5. Plain white labels or possibly a boilerplate label with "artist, song title, label" info handwritten onto the labels. No printed cover. A few go to the label, some to the band, for listening to and final proofing before the "go ahead and make us 1000 copies" order is put in. It's very rare that there is a change to an album once the test pressings have been created and they are almost NEVER available for sale to the general public. I've mostly only seen them for sale after the album comes out, strictly as collector items.
The $50k asking price may be ridonkulous, but the demand for this one-off game makes perfect sense to me in light of what i've seen people get stupid over in the vinyl world.