A good franchise is going to be able to tell you the most effective ways to set the business up, the best ways to market and staff the business, and the best practices to run it on an ongoing basis. Though you may be able to do many of these things on your own, you'll probably go through some fairly expensive trial and error before you get it all figured out.
There's a lot more to starting a business successfully than simply having enough capital available--though this is certainly very important. You should carefully think through all the other aspects of what you need to do (writing a detailed business plan is always a good method to do this) and how you are going to do it, then decide whether an established franchise system is a good investment for you.
Jeff Elgin has almost 20 years of experience franchising, both as a franchisee and a senior franchise company executive. He's currently the CEO of FranChoice Inc., a company that provides free consulting to consumers looking for a franchise that best meets their needs.