system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Why are the Weasleys so poor?

They are a pure blood family, which implies that they are a pretty old family.  Every other pure blood family we are introduced to is pretty well off.  What's the deal?  There aren't many pure blood families, and in order to stay purebloods most intermary at least somewhat.  Are they just decendant from a single poor family and inbred, or did they keep marrying poorly?  Hell, just through inheritence their family should be doing better than it is.  Was papa Weasley's dad just a bad gambler or something?
gpt
They seem to be known for having big families. That would whittle down any estate after a few generations. Molly Weasley is also a full-time mom, which limits their income a bit, while Arthur Weasley is both honest and not terribly ambitious. 

That said, they're easily the happiest pureblood family we've ever seen. Great home life, and that's no accident.