Oh, I've been trying to get the game only recently and have had some time finding it for a decent price. Almost bought a copy for $30+ for a used copy on Ebay so I got pretty excited when I saw it for 20 lol. My bad.
To be fair, this game has been out of stock for a while on Amazon, and they had problems with the last shipment they were supposed to receive, resulting in some canceled orders. My order was one of those affected, so I appreciate the update. While $19.99 is the MSRP, Amazon is really the only place you can still purchase it new, and whenever it goes out of stock, the other sellers always mark up their prices. The lowest price before the most recent restock was in the range of $80, so there is decent demand for the title still. Square doesn't even sell the game on their own website anymore, and they had been for the better part of the last year. I had been waiting for a sale for a long time, but with only 400-ish copies available (versus the 1000+ for Dragon Quest V and the restock of Kingdom Hearts: BBS), I'll happily take MSRP for this one to save me the trouble of constantly watching it.
In short, thanks OP for the news!