I was able to find a small ESC for about $12 off of ebay. If you were designing a robot, would you see that and think?
\$12 bucks for an ESC that connects to simple pulse-wave interface - sign me up!
Or would you think:
\$12 just to control a motor? I could throw together an H-bridge for $0.50 and be done with it.
My robot in particular actually has two motors and therefor $24 to control the two of them. But the interface is really easy (plus has the added advantage of being R/C vs computer controlled with a simple change of connectors.
Which way would you go?