Willoughby no doubt wishes he had Brandon's wealth and position, but he isn't willing to take the necessary steps; it would mean giving up his expensive ways, which is no doubt why he mocks Brandon's "two new coats a year." But I think he also envies Brandon's virtues. I believe Willoughby discerns how Elinor respects Brandon and wishes he could inspire that esteem, too---but again, he's not willing to do what is necessary. I'm oddly reminded (of all the weird things) of Scarlett O'Hara, who always intended to be just like her virtuous and charitable mother . . . when she's older, because if you're kind and unselfish when you're young you miss a lot of fun. And Scarlett doesn't really want to be kind and unselfish; she just wants the reputation for it. And so it is with Willoughby. He'd love to respected and esteemed, but I think that "in essentials," he would be "much as he ever was." Just my two cents.