Becoming a reseller should not be taken lightly. If you are going to start with a reseller plan from another company such as Hostgator make sure you do your research into uptime reports, support and other issues that could potentially affect your customers. Going in blind is probably the worst thing you can do. Also as a few others have pointed out cheap is not always the best. What is going to be most important is to make sure your customers have a stable system to host on.

I would also decide on a niche market to concentrate on. One that allows you to charge a premium for better hosting solutions. The low end of the market is so overrun these days that making money is almost an uncertain prospect and hosting at this end of the spectrum is more a commodity now then anything else. You really need to offer additional services to make any money on the low end of the hosting market these days.