When you hit 30 there are a few things you stop doing. You stop going out regularly on a Friday night and opt for brunch instead. You decide that watching Poldark on a Sunday is preferable to the pub. You like a bedtime that doesn't fall in the a.m. You also stop buying stuff that's cheap. Instead, you start making much more informed choices. Based on experience, there are five key pieces that you don't want to ever scrimp on again as you get older. Essentially, they are fashion kryptonite for 30-somethings. Find out what they are by scrolling for what not to buy when you hit 30 and shop better pieces now.