Guess it depends on price and what you want it to look like. Essentially a new kegerator is just a mini fridge with the mods already done to it. I have a keezer (that I built), and a Sears kegerator. I love both for what they are. I love the kegerator because of the look. I replaced the single tower with a double and I love the chrome rail that runs along the sides and back. Not sure how easy it would be to get the rail to place on a mini fridge build. That may not even be important to you. You need to figure out how much money you'll have invested in a build and then price a new one, ready out of the box, and see what works best for you.