Professional photo retouch employee portraits

We have around 40 photos from our employees and want to have them retouched for campaigns and ads. We want them not overly retouched but things like under eye circles,, teeth whitening, skin retouch, making some of them a bit slimmer, retouch wrinkles and spots in clothes, improve lightning, make eyes a bit more glowing...
Please show me some of your works you have done previously and tell me price per image.