What is the value of 1926 walking liberty head quarter with mint mark m?

To clear things up:

> It's a Standing Liberty quarter. The Walking Liberty design was used on half dollars.

> M is the initial of the designer, H. A. MacNiel. The mint mark position is on the opposite pillar next to Miss Liberty's foot.

> A "walking head" would be pretty interesting, though anatomically impossible....

Please see the Related Question.