Talking about the investment it all depends. If it is like brother asked in his question $10000 gas and $2500 grocery, then i would say probably about 750 thousand to 1 million initial investment. 

                                      The example i give you above is a vague example, in business there is always more or less then expected.In the above example we only calculated for 1 employee, but in reality there could be 2 or more then 2 employee working at the same time bringing the profit down. there is always high risk associated in business for a big return.