Implied option volatilities are often not constant throughout the range. This is due to a variety of reasons, and in many cases more than one reason is at work in a particular situation.
Your trade idea would allow you to make money only if implieds move down at the strike you have chosen, or your cost to adjust the position over time is more than offset by your positve time value decay. As a result, it does not let you capture the "edge" which you perceive, if in fact this "edge" exists.