You could wait, like I'm doing, and see if they slash it again before it goes completely out of stock. I picked up a $90 pink model for a friend at work. (he wanted a Christmas present for his daughter) But for myself I am waiting for a lower price. With the way Target clearance works, the next cut should drop it below $70.
The obvious drawback is that once their stock is gone, its not coming back. So you ride a bit of a line. Stop by your local Target, and poke around their video game department. Check some of the nearby endcaps to find their clearance items. If they have some DSi XLs, make a note of how many, and then check back in once or twice a week. Clearance items at Target keep getting cut in price until they sell.