I agree that Darcy probably settled a pretty liberal amount of pin money on his wife, for a couple of reasons.

First, "what might be called economy" strikes me as one of JA's sarcastic descriptions.

Second, as we know, gossip about money was common, and the information managed to get around. A man in Darcy's position would, at the very least, not want to look like a tightwad in comparison with other married men.

Third, and most importantly, Darcy would expect his wife to keep up appearances in her new station. Lady Catherine wouldn't be the only person in Darcy's social circle to be asking, in effect, "Who is this woman, where did she come from, and what is she doing here?" Elizabeth was going to have to show that she belonged where she now was. Part of her task would be to strike the right note of display, not too ostentatious, but not too frugal either. Darcy could rely her good sense and good taste in doing so if he put the wherewithal in her hands.