From what I understand, you are trying to help an SEO agency sell to other agencies that themselves sell to dental/medical companies? It's tricky without knowing more details, since this question keeps coming to mind: Why is the SEO agency interested in white-labelling their services to agencies...
That is a LOUSY return. You'd be better off putting the money in a savings account in the bank. I do not know your industry well, but in mine (Marketing Agency) I aim for a net profit of 15% after paying corporate taxes, wages and all overheads.