From what I know about this field is that you would have a very tough time competing
There are a lot of companies (mostly oriental, from what I`ve learned) who provide in-game support services such as money making and supply and other in-game services (such as powerleveling).
The way I see it, the main issues you`d have to deal with would be:
A. Time consumption vs money earned. It`s not easy and fast to do it, else everybody would. and prices get lower all the time
B. Target market. Your target audience is mostly under-aged teens with little money to spare. (and usually no credit card)
C. Reputation. People (especially the not so younger crowd. e.g. late teens) would suspect these types of services to be illicit, or simply just a scam (pay up and get nothing in return)
If I were you I`d research this thoroughly before jumping in. But hey, that`s what I`d tell anyone going into business.
Plus, you never know what idea would jump-start your career
Hope this helped, and the best of luck