The best way to badaling and ming tomb at the same day

I'd like to visit the badaling-great wall and ming tomb at the same day. What is the best way you sugguest me? How much does it cost by taxi if the rute is beijing down town-badaling-ming tomb-beijing ? We are 4 persons in one group. At first, I intend to take bus tour but it seems that we will just have a short time hiking to the great wall and just one hour to visit ming tomb. Any other options besides taxi and bus tour? I need a comfortable transportation since I have 2 children with us.