Anyone of any age can be homeschooled, it's just a matter of how much time and money it will take, given your situation and level of education. In your case, your son is high school age?, so you're looking at a lot of high school and college prep material. You'll need textbooks, and some of the more difficult subjects may need to be covered through online courses or community college. You'll also want to follow up the more advanced courses with nationally standardized exams such as AP, CLEP, or DANTES. The good news is that all this preparation pays off, since your son should be able to test out of at least the first year of college, which is generally just remedial high school courses for the people who didn't learn the coursework properly the first time. He'll also be able to save time by skipping "fluff" courses and not having to transit back and forth from school, which means he can spend more time specializing in the subjects he's good at, or building up his extracurriculars.
I'm not sure how well this answers your question, but it should give you some things to think about. Let me know if you need any clarification