starting from no credits, how much would a good online degree cost?

The problem in answering your question is defining a "good" online degree. Many employers won't accept applications supported only by "online" degrees, and often the credits from those degrees won't transfer and are not accepted by other academic institutions or graduate schools. Your first step is to determine what subject you wish to study, and find out for sure if any online degree from anyone will open up job opportunities for you. If online education is widely accepted in that field, then the cost becomes a worthwhile consideration. If, however, you discover that you will not be competitive when it comes time to apply for positions in your field, you should ignore any concerns about how much the degree might cost, and instead focus your attention on earning a credential which will have more ultimate value.

no