If it only saves you once from going down due to the surface, or some jackass cutting you off or cutting in front of you.. it'll be worth it.
For the last 4 years, I've been riding a bike without ABS.. no incidents. New bike, 800GS, in November, I was riding home from work in the rain, I see a car in the opposite direction waiting to turn left in front of me to go into the parking lot of a bar on the opposite side of the road. I keep an eye on him.. he seems to see me, he is stopped.. then he proceeds and turns in front of me, then he stops just before I hit him... I grabbed a handful of brake, and at the same time steer around him.. and by the way, the road was wet from the rain. I am sure I would have gone down if I had braked as hard as I did on a wet road if I didn't have ABS, plus I wouldn't have been able to steer as I was braking very hard.
I looked over as I cleared the hood of his car..... old guy..
So... ya, it's worth having, especially on the unpredictable roads of going to south America.