Photo editing - Adobe Photoshop

I have about 100 photographs of antique tobacco tins which I have taken in a light box set against a white background. The images will be used for a book in which the pages will be black. I need the images of the tins "cut out" from their current white backgrounds and set on a transparent back ground so that I can do things like over lap them etc in the book layout. Most of the pics are taken front on as in the attached examples. Some are taken from an angle to give a more 3D look. I have previously had a quantity done and found the best way to approach this is on a cost per image basis. Once I establish that I can work out exactly how many photos need to be done. I have attached a before and after sample to illustrate my requirements.