Doctorate

I have been thinking about not stopping after I get my masters degree. I am very unsure though. I do not want to spend more on my education, than I will make. I also do not know what schools are good and if there are any online schools. The only way  I would make good money with my Doctorate would be to teach college. I do not know if that is something I would want to do. I love teaching elementary, but I am not sure I would get paid correctly doing that with a Doctorate. Does anyone have any advice? Or maybe some of you are thinking the same thing?