AU Front lower ball joints.

[5.0 ED]

So a couple weeks ago i had the car on the hoist and went thru and checked everything and all was good, front ball joints had no play and so on, last week i had a squeek in the front, a couple days later it went away, tonight i get in the car and as i drive out my driveway i have a grinding sound, i stop check everything and cant find anything while car is on ground, figure probably a plastic shield somewhere hitting the wheel, and i drive to my mates place 20min's away, on the way i notice steering is now crooked and bump steering a little, and then the sound gets worse, it was originally only there when full lock on steering, now its there from half a turn either way. At my mates place i jack the car up and yet passenger lower ball joint is completely stuffed, has well over 5mm play in it, now my question is are these common for just giving up, im accustomed to ball joints slowly wearing out, not good one week stuffed the next.

Also anyone have any idea where i might buy a new one tomorrow Sunday?