Here's an example of how I would do a basic reference sheet commission since I have been asked for it on more than one occasion.

-3 poses (as well as any specific details that require magnification etc)
-Shading and color
-Simple gradient BG

Since reference sheets aren't very specific in pose or action, they are cheaper. Normally, it would be extra for more than 2 figures, but the cost would be that of the base amount (2).

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