Realistic Goals for Clickbank eBook Product?

Asking for a realistic information with no data is not a good idea, especially on here. We dont know your landing page, we dont know your product quality (refund rate is a profit killer if too high).

My advice, do your split testing first. Promote via ppc, test and tweak. At the end of the month, if you are losing money, then move on because it will be the same for your affiliates as well. You need a tested, tweaked, converting product to make money as a vendor on cb. Otherwise, it will be a time waster money pit.