I believe it's the cheapest price of the game thus far on PS4, and is cheaper than the best Steam version price ($29.99 USD) and comparable with the cheapest PSVita price ($22.95 AUD), although this one is the physical version.
Stocks seem to be pretty limited, although delivery still seems to be available as of this time. I doubt it's going to be restocked, being a NIS America published title (experienced this plenty with their 3DS titles).
For those interested in the series for the first time, linked is the recommended playing order. The main series games play as an adventure murder mystery game, mixed in with court action (closest series would be the Ace Attorney games if you've played those).
Also linked is the full range of JB's 2 for $40 promotion.
Also has things in common with the Zero Escape trilogy for DS/3DS and Vita.