I am currently designing a hexapod with a total of 18 servos. I come from a computer science background and know little about electronics, so there is one thing which puzzles me. Adafruit is selling this servo shield. It can power up to 16 servos while only using two pins. But it's quite expensive as it would cost me ~30€. Add the cost of an Arduino Uno and you are at >50€. At the same time I could just buy an Arduino Mega and power all Servos for a lower price.
I like to think that Adafruit wouldn't sell a uselessly overpriced product, so would there be any advantage to using this shield?
Bonus question: If I'd end up buying the shield, could I just power 16 Servos with the shield and 2 via the Arduino? Would there be any problems with that? Like a delay in the 16 motors or similar issues which could through my kinematics over bord? Would I have to buy two shields (which is not really an option at that price)? Any other suggestions I have not heard of are also very welcome!
If it is of any relevance, I am planning to buy these servos as they are pretty strong and come super cheap in bulk.