Hudson Game Music by G.M.O. Records has recently become very, very expensive - for reasons which aren't clear.
Prior to 2016, the most this album ever sold for on YJA was 13,500 (all without obi). But after that, the three subsequent sales have been:
11/2017: 25,000 yen (no obi)
03/2018: 49,500 yen (no obi)
06/2018: 102,000 yen (with obi, but likely very faded on the spine).
If we look at Amazon JP, prices there are similarly sky-high. They have 2 copies for 130,000 yen, one which is with obi (the obi is kind of beat up).
At least in recent years, I know of no other album whose price has spiked this hard. This is a ~4x increase over a two year span.
In my case, this is an album for which I'm hoping to get a complete copy. Unfortunately, none of the options here are very good.
One option is to pay 130,000 yen for an Amazon copy with a beat up obi.
Another option is to wait for a complete copy to appear on YJA. Though only one complete copy has appeared in the last 10 years (the 102,000 yen one). As a result, there's no telling when the next one will appear. And when it does, it could very well go for more than 130,000 yen.
A third option is to wait for a store (e.g. suruga-ya, Mandarake) to get one. Stores aren't paying much for the album (e.g. 7,000 yen or so). This means they haven't caught up to the market. If these stores ever do procure a copy for sale, it will probably be cheap (relatively speaking), but potentially not complete with obi.
A fourth option is to hope prices come back down. No idea whether or not this is wishful thinking...