From my 4 year web hosting business experience, I would recommend you to start your business with a reseller account. It is the most logical way to start a web hosting business. It requires only some $10-$20/Month. You can choose your reseller account from the many available reseller hosting providers out there.
Why not start with a VPS or even a dedicated server? Well, there is no point in doing that, unless you already have a substantial amount of clients to begin with, plus you already know what you’re doing. For VPS you have to spend many additional cost like cpanel + whm + whmcs licence fees + Dedicated ip + many more. Also if you are starting from scratch and if you are newbie, as not much skill don't go with VPS or a dedicated server, you will cry surely.