It might sound a bit discouraging but I think you have only half the money you need to start something going with reliable commercial scale machines. You have no background in machinery so it would be a risk buying used as they can nickel and dime you to death if you cannot do repairs/rebuilds yourself. This leaves you faced with buying new and a combination such as a Haas VF2 mill and TL2 lathe would need all of your $100,000; any other brand of machine is going to be the same or more expensive. Then as mrainey mentions you need to have the resources to getting tooling and all those other things he mentions. If you had several years experience working on machines and had contacts in the business then 100k would be plenty to buy two machines and start a sideline business while keeping your day job, and over a period of two or three years with a lot of luck and hard work, develop this into a fulltime, viable independent business.
An open mind is a virtue...so long as all the common sense has not leaked out.