The grilles are not discontinued. I'll say it again you can get them from GM, it just pays to shop around to see what dealer will offer the best deal. Now that he's said it's the base model grille I checked and Rydell appears to be cheapest at $140. Always important to watch what you're going to be charged for shipping as it seems to be all over the place depending on dealer.
LMC is great for stuff that has been actually discontinued and they have bought up all the stock, but otherwise no sense in paying their inflated prices.
Richard
Just looked up a bunch of stuff on GM Parts Direct and you're absolutely right, they're still available. No idea why I thought they were discontinued... Brain fart I guess.