Thing is, in the US, there is an understanding of a class 'difference' between nouveau riche and old money; I'm not really sure where the writer(s) of that episode were living, perhaps under a rock.

I mean, The Beverly Hillbillies, which is emblematic in US pop culture, takes that very issue as its major plot point. More recently, I think it's been touched on in Gossip Girl, The OC and the whole Real Housewives of [Place] phenomenon...

But it's not really explicitly delineated, really all implied, which could be part of the issue.