It's completely up to you what you charge. As the reseller servers aren't branded to lunarpages, and don't use "lunarpages" nameservers, your clients shouldn't know it is a lunarpages server.

It's a bit like being a supermarket. You get a product from wholesalers. People can go and buy food direct from the farm, but some will be happy not to.

I'm not sure what most of our resellers charge, I'll leave the others to add their input.