I think people sohlud not try to control over judge how their friends spend their money, as long as said friend has their sh*t together and isn't hurting anyone (aka stealing or scheming from others) for said purchase. I would, however, appreciate a cautionary word if I, for example, spent frivolously and am failing to see it. I would also caution my friends if this happened to them. But in the end, we're all adults and no one needs or wants a micro-manager/nagger that constantly passes down their own judgments on us about our spending.