Servos are invariably the most expensive component in robot design. Of course, as you increase the number of degrees of freedom, which typically requires one or more servos for each additional degree, the total robot cost quickly skyrockets. At the same time, you want to optimize the robot's performance and ability.
Leave it to Azusa Amino, a champion ROBO-ONE competitor and designer of the delightful Toko Toko Maru humanoid robot, to come up with a hexapod robot design called “Tic-Tak” (Tic Tac) that only requires six servo motors yet was able to capture 3rd place in the 1st Kondo Land Robot Contest, an extremely challenging steeplechase/obstacle course that defeated almost all of the competitors.
Amino is very active with robotics at the hobby, professional, and academic level. He's traveled all over the world demonstrating his robot creations, including participating in ROBO-ONE Gran Prix exhibitions in Hong Kong and South America.