Generally speaking, how long does it take to create an Alexa skill?
Clearly "it depends", so let's assume someone has programming experience, and the thing to control has an easy to call API.
On the surface it seems trivial. If words spoken, then call api. Mixin a few variations for usability. But most (all?) things are harder to code than they seem at first glance.
One example is the new AV support. Thinking about creating a skill for Onkyo receivers, since they don't seem to be working on it.