Sorry but $50,000/year for Harvard puts your family above middle class. There is a lot of room between upper income and top 1%. Now, I still think the idea of Wash U for undergrad and shoot for Harvard for medical school is a good idea.
I will question the double major with business though. It’s a great major but surely a distraction from premed. Finance courses aren’t as easy as some might think. And most business schools have around 60 hours of requirements beyond the general distribution requirements. Take a few business classes on the side. Micro and macro econ, intro to marketing, maybe an entrepeneurship class.