I agree with the previous posts, let me just give you my 2 pennies worth as I had a restaurant that failed in it's first year. First of all it is not just about opening the door. You will have to have a good cushion, lets say enough money to run it 6 months to a year at a loss. People don't know you, it will take them weeks if not months to come in for the first time. This is what made me close my place, people just started coming back but I couldn't keep up with the rent and the bills. The type of restaurant you want to open can make huge difference too. Fine dinning will require a set of skilled people that do not come cheap. A large menu and not enough costumers will result in a lot of waste. I have been to an Argentinian restaurant the other day that really impressed me, a simple operation they specialize in meat one chef on the grill one dressing up the plates/washing up. Two of them doing 50 - 60 covers no problem.
As people said before me it is a cash business which makes it vulnerable to people with sticky fingers. I live in London and this problem has prompted a few places NOT to take cash any more, cards ONLY but the jury is out on this I haven heard yet how they are doing....If you thinking of opening the place and then handing it to a manager to run it forget about it, you need to keep everything tight, every day. Majority of people in the industry will tell you that this is terrible business to be in, and it is true, rewards are very small for the effort and money you put in. I don't want to be discouraging but it is better if you go in it with your eyes wide open. I have worked for a few people with what I call Casablanca syndrome, they think they are Humfrey Bogart running this fictional place and all they do is go around and tell waiters "Champagne for table 8 on the house", if only the real thing was like that....Soon they were out of cash and I without the job. So a few thing to consider, on the other hand when it works it is a beautiful thing...