First decide which coloring books you need. Do you need pink dolls for girls or trains for boys? What age level of coloring books are you targeting? Narrow down the type of coloring books you want or need before placing an order.
Check out dollar or discount stores for bulk coloring books.
Often toy stores or party supply stores sell bulk coloring books.
If you buy often from a provider of bulk coloring books, ask for a frequent buyer discount.
Buy in bulk to get free shipping or reductions on shipping fees.