I think that Target has the absolute best deal on baby clothes. Better than Walmart even. I just got the cutest little t-shirt and shorts set for only 6.99. And that's not even a sale price. It has a skull and crossbones on it and says "Trouble Maker." And I found a cute little t-shirt on the sale rack that has AC/DC on it. I'm not a fan, but I'm mildly goth, and this is the closest I can get to gothing up my little guy. There just isn't a huge selection out there. Spencer's has a few cute things, but they're all too expensive, and some of them, although cute and funny . . . I just can't bring myself to dress my one year old in t-shirts or onesies that have curse words on them.
Although I like Target's clothing for babies better because of the prices and styles, Walmart is the only place that I've seen preemie clothes if you happen to need those.