(Image credit: Getty Images) We've all read stories about the budgetary wonders of self-restraint. You know the tale: If those darned millennials gave up Starbucks and avocado toast, we'd solve the housing affordability crisis or something. I don't actually know. I don't read those stories. That's precisely why I laughed when my editor brought up a question she'd seen a few times from readers: "I can afford a nice car. But should I suck it up for a few years with my current vehicle, and use the money I'll save not making payments on a new car to invest instead?" From just $107.88 $24.99 for Kiplinger Personal Finance Become a smarter, better informed investor. Subscribe from just $107.88 $24.99, plus get up to 4 Special Issues CLICK FOR FREE ISSUE Sign up for Kiplinger’s Free Newsletters Profit and prosper with the best of expert advice on investing, taxes, retirement, personal finance and more - straight to your e-mail. Profit and prosper with the best of expert advice - straight to your e-mail.…