But I've found it very reasonable and you can purchase whatever quantity you want. (toughnickel.com)
He purchases these books in quantities he wants and sells them at nearly a 50 percent margin. (accrispin.blogspot.ru)
If for any reason you can not specify the additional mice or specific quantities you want, please write your detailed request on the «Shipping Instructions / special notes» section of the Miscellaneous section of the checkout process. (mmrrc.org)