This is not what you're taking about because it is not the Echo hardware, but I think Amazon lets hardware manufacturers access Alexa API from their devices, an

This is not what you're taking about because it is not the Echo hardware, but I think Amazon lets hardware manufacturers access Alexa API from their devices, and those hardware makers can charge whatever they want (and could put whatever type of "app store" or "hackability" into their hardware, all of which could call the Alexa voice API: https://developer.amazon.com/alexa-voice-service https://developer.amazon.com/alexa-voice-service