I would grab it. Whatever is offered (and as Buenchico says, it may vary a lot), it will be better than economy, and over 12 hours that does make a difference. The usual is more knee room, probably wider seats too and a better menu. The extra price is usually the big killer.
Be warned though that it will raise your exit tax sharply, and this may not be included in the bargain price.
if you like the price, go for it. My guess at what it would involve was all wrong (I was thinking of premium economy); business class in big airlines these days is basically first class. Take it, take it.