My son graduated from high school with 30 college credits from the community college. I think it would be very difficult to take enough classes to actually earn an associate's degree, which requires 60 hours. Maybe someone on the forum has a child who has done it though.
You'll need to research carefully and decide how you want to proceed. There are scholarships available for homeschool students, just as there are for other students. Most colleges that I know of don't have money set aside specifically for homeschoolers though. What you'll need to research is the monetary difference between incoming freshmen scholarships and transfer student scholarships. If you count the dual credit hours as college credit when applying for a four-year college, he won't be admited as a freshman and won't be eligible for freshman-only scholarships. On the other hand, many colleges, especially public universities have generous transfer scholarship available, especially if they have good grades.
We did not pursue any CLEP credits but I do know of others who have used that method for college credit. Again, be careful about how much college credit he earns if you are interested in freshmen scholarships.
You might get a better response if you post on the high school board.