In Season 4, Nathan and Haley have no health insurance. And yet the girl's walking around wearing Uggs. And they sure didn't look fake.
Haley could have just been given them as a present by someone.
It could be argued, what exactly does Haley even see in Nathan? He repeatedly acts downright neglectful of both her and Jamie in his vain attempts to relieve his sporting glory days... seriously? You have a beautiful wife and a great kid, and you think Basketball is the only thing to make you happy... what the hell, man? Its remarkable she didn't leave him a long time ago.
It was that basketball was taken away from him, nothing else. When he retires from the sport at the start of Season 8, he's a lot happier since it's his decision. As far as being neglectful, he's only negligent when he's in the midst of his depression. When he snaps out of it, he's not trying to make a comeback, he's simply trying to walk again. It's only after Jamie is nearly kidnapped by Nanny Carrie that he even considers making a comeback, and that's with Haley's support.