Mr. Bingley inherited property to the amount of nearly a hundred thousand pounds from his father, who had intended to purchase an estate, but did not live to do it. Mr. Bingley intended it likewise, and sometimes made choice of his county; ... Mr. Bingley had not been of age two years, when he was tempted by an accidental recommendation to look at Netherfield House.
There are several things revealed about Mr. Bingley along with his age, which is less than two years past the legal age of maturity at 21, thus about 22 years but heading toward 23. What is revealed about Mr. Bingely is that he inherited a large fortune from his father, which is what puts him in Darcy's class and social circle. He wishes to fulfill his father's wish of purchasing a family home but has never been brought around to actually doing it because of his easy going nature. It is also revealed that, quite unlike Darcy, his father made his fortune through success in business, a fact that Miss Bingley conveniently ignores when she is exerting her pride and arrogance over others, for instance, Elizabeth and, later in the plot, Jane. One other thing that is revealed about Bingley, though unconnected to his wealth or age, is that he is not in love with Darcy's sister, thus Jane's romantic path is clear of competition and obstructions.