Yes. Which is the big problem with robotics. No volume and high tooling cost. With enough money, something like Big Dog or Atlas can be built, with large numbers of custom moving parts. But the price tag is in 8 figures.
Other than the industrial robot arm people and the vacuum cleaner people, nobody is making money in robotics. (Well, the individuals who were bought out by Google exited OK, but overall, the Google thing was a lose.)
Other than the industrial robot arm people and the vacuum
cleaner people, nobody is making money in robotics.
FIRST robots are moderately interesting, but cost something like $5K-$10K each. VEX and Lego robots are cheaper, but are basically toys. (I work with VEX) Think erector sets with microcontrollers bolted on.
Press video for the 2016 VEX World Championships. Thousands of people. https://www.youtube.com/watch?v=0Y1YiGZv_F4
That said a few groups have done it. Heavily optimized drivetrains can be ~96% efficient at the right speed and torque. Extremely precise drivers can regen at 98%+. If you charge gently enough batteries can be 98%. 88.5% total efficiency. That's extremely good, enough to reduce power consumption by 8.7 times.
It's better than a human but not quite as good as an insulated spring.