I would suggest you make the packages as small as possible and charge as much as you can get away with.
You price based on what it costs you to produce the work.
Your pricing has to cover all your costs: equipment wear and tear, pre shoot time, post shoot time, props, backup disks for your computer, electricity for the computer, image editing software, shipping charges for the prints, etc, etc, etc.
What do you charge up front (sitting fee)?