It's definitely a layout sketch and its value 
would not rival a genga in the true sense of the 
word "genga." This means a genga drawn by the 
character designer or director or someone whose 
name is readily known and connected to the way 
the anime looks. Those gengas are highly sought 
after and can be really $$$. For instance, I have 
sketches and other preproduction work from 
several Miyazaki films. If one of those were 
drawn by Miyazaki, I'd be in heaven (and really 
broke). Otherwise, the sketches are "relatively" 
affordable for me ^_~.

I collect genga/sketch work mostly because I love 
to see the process of animation and layouts are 
really neat because you can tell what the cel is 
supposed to look like (plus if the BG matches or 
what have you). To me, they are valuable but not 
necessarily monetarily so!

Hope this helps and I welcome any corrections :)

Wendy