I have no idea what something like that should cost.

As an alternative...

You have put a lot of work into your web site.
What if you put the images up on your site in a gallery that allows the viewer to purchase them.

1. you only have to print what's ordered.
2. you could probably offer all images as apposed to only offering the best.
3. the increased traffic to your site will help to showcase your other products.
4. you will have more options for ways to sell the images, framed, matted and framed, etc.

Just a thought,