"When would an earned fortune like Mr Bingley's go from nouveax rich to 'old money?'" Bingley clearly has the fortune inherited from his father. If he wants to establish the Bingleys as gentry, he must acquire an estate. His sisters were anxious for him to do so. Presumably why he leased Netherfield. 'Respectable'old families usually took 2-3 generations to fully establish themseves. But appearances of refinement and gentility and 'distancing' yourself from the trade basis of the family fortune could help establish you in society, just ask the Bingley sisters. Perhaps this is why Mrs Hearst chose to marry a man 'of more fashion than money'.Importantly, you could also gain social acceptance by marrying a woman of an old landed family. (Actually, although Jane has no dowry when you consider she is the daughter of a landed gentleman, perhaps her by birth she's not such a bad match for Bingley?) Admittedly with his 5 thousand pounds ann. he could possibly marry a lord's daughter and so help establish family connections. Clearly, Bingley has a useful connection and friend in Mr Darcy. Indeed, I think with a friend like Darcy who has connections to the nobility, his palatial estate and income; Bingley will be accepted into landed gentry quite easily. I think there were various ways to achieve social status. He may also act as a local JP. It would be interesting to know what great marriage his sister Caroline finally decides on!