It is kind of hard to wrap your brain around, isn't it? Plus the fact that they either were living below their income at one point (before they had kids) or had to diminish their lifestyle with each successive child, and as they got older. The perspective on money was certainly different back then, when you had what you had and that more or less stayed the same over a lifetime despite a growing family etc., rather than now when we expect to start out on a small salary and get raises and cost of living increases etc. as we become more valuable workers and also have more expenses. I don't know what magical thinking Mr. Bennet must have employed to allow him to do that.
That said, you do have to remember that land typically only brought in about 2% while cash brought in about 5%. Selling off half the estate would still leave the son with an income of a thousand a year while providing fifty thousand pounds to be divided among the five girls. Not a vast fortune, but five hundred a year apiece would bring them comfort and independence, and their mother would have her own inheritance to keep her comfortable as a widow, as well as probably living with a daughter.
That said, you do have to remember that land typically only brought in about 2% while cash brought in about 5%. Selling off half the estate would still leave the son with an income of a thousand a year while providing fifty thousand pounds to be divided among the five girls. Not a vast fortune, but five hundred a year apiece would bring them comfort and independence, and their mother would have her own inheritance to keep her comfortable as a widow, as well as probably living with a daughter.