I can tell you my personal opinion. If you buy a franchise, your getting the customer base right out the gate. If you purchase the rights to Subway for example, you get their menu, the ingredients, and the hundreds of millions of people who already know and love subway. However, you have their monthly franchise fee.
If your absolutely positive you can build your own brand, then privately owned is the way to go. Over the years you can build a great customer base and not have to pay someone else for it.
Thats the biggest thing about buying into a franchise, The name reconision and free advertising. Like I said before a friend of mine owns 6 Subways.
To buy into one you have to have a min. 100K up front.
To start my own sammich place the over head would be high right off the bat but there is no monthly fee like you said. The same with the outdoor gear place.