Not sure if this is a planning question or not really.
To make any money out of it you need to have a good list of clients who wish to buy hosting from you. You need to work out how many clients you need and what price you would charge. I have a reseller account but I dont really use it to make a profit. It just covers some of my costs.
I doubt you'd make money reselling to be honest. Usually you'd offer hosting to clients just so you can offer a complete set of services. It also makes things easier if there are any problems as you have full access to their hosting account.
Yeah the other problem is that if (or rather when) your server goes down, you will have loads of angry clients phoning who wont blame the hosting company, but will blame you!