I made this mistake about five years ago when I was getting back into cycling after cycling a ton as a young pup. Bought a decent looking MTN bike at Target figuring I could nurse it along until I could save up for a decent roadie. To make a long story short, one night the front tire flatted for the fifth ride out in a row. I was so fed up, I threw the bike down the street for a block before leaving it on somebody's front lawn.
Fast forward a couple months, saved my money and got a classic steel Bianchi roadie. Built it up with Campy components. I've since upgraded to a new Bianchi EV3 and got a Volpe for commuting and touring. My mileage has increased exponentially over that last few months. Looking to do some racing and touring next season. I'm in love with my bikes. Good frames, components, and assembly make a huge difference.