Why is Pip concerned batou buying Herbert a partnership in a business, AND what does this reveal about Pip?

Pip is concerned about money and his friendship with Herbert.

Wemmick initially says that Pip will lose both his friend (Herbert) and his investment money.

Choose your bridge, Mr. Pip,” returned Wemmick, “and take a walk upon your bridge, and pitch your money into the Thames over the centre arch of your bridge, and you know the end of it. Serve a friend with it, and you may know the end of it too,—but it’s a less pleasant and profitable end.”