Overqualified really means that you have experience for which we are not willing to pay. It is not relevant to the fact that you will accept what they are willing to pay. They think that you'll bolt as soon as you can get what you are really worth.
Really, how can you be "overqualified" to do a job? If you are willing to do the work, what sense does that make?
I had an employee who had a doctorate in pshychiatry and I hired her to write code. By most considerations, no one would hire her to do this "menial" work. She was my best employee.
Cindi