In relation to US design patents and regarding filing, a few points must be noted:
If you qualify as a small entity, then the fees are halved.
If the filed application is over 100 pages then for each additional 50 pages, an additional $270 is assessed (small entity status does not apply).
In addition as to the use of pictures, under (Manual of Patent Examining Procedure) MPEP 1503.02 (Drawings), drawings are normally required to be submitted rather than photographs.
The drawings are normally in black ink on white paper. For confirmation of this see 37 CFR (Code of Federal Regulations).
Photographs are acceptable only in applications in which the invention is not capable of being illustrated in an ink drawing or where the invention is shown more clearly in a photograph.
If the subject matter of the application admits of illustration by a drawing, then the examiner may require a drawing in place of the photograph.