£10,000 per year for Mr Darcy is 10,000 gold sovereigns per year. A gold sovereign at spot price today is about $1,100. So that’s over 10 million dollars per year in gold-equivalent wealth. Plenty to maintain his estate with.

Alternatively, £10,000 is 200,000 sterling silver shillings per year (20 shillings per pound) for him. A sterling shilling today is about $13.50 at spot price. So that’s $2.7million per year in silver-equivalent wealth. Still plenty!