that 50 dollar gap, while important to us, i dont think will matter in the long sceme of things. 
if there's one thing working retail has taught me, is that parents, while some of them DO bargain hunt, and more into getting the kid EXACTLY what they want, as opposed to what would be the better deal. 
though one could argue, getting the parents to plop down 200+game in March would be a bit far fetched (espesially the ones who will be "I JUST GOT YOU A DS FOR XMAS, WTF")
it's going to fly off the shelves regardless due to the fact that sony has mastered the "I GOTTA HAVE THAT" retail persuasion.
hell, i've got 2 PS2's in the house (US/JPN), and i STILL wanted a slimline
so to answer your question? parents will pay. but probably not in march.