Are you comfortable with a dedicated environment? If you can monitor the server, you can chose to resell on just a portion of the box, and either split the rest of the box with someone you kow / trust, or target other resellers to and create "power reseller" accounts n the unused portion of your box.

If what you are doing works for you, keep on doing it! Depending on your budget, a dedicated server or two may save you a ton over a bunch or reseller accounts here and there.

Also, if you are not confortable in the dedicated environment, I would not do a dedicated server as you know have a whole new list of things to manage / worrie about.

Good luck!