Greetings. Chemical peeling - is a good form of treatment for both acne as well as for post acne marks or post inflammatory hyperpigmentation. The cost largely depends on the place and specialist treating you - more so due the specific peel that he or she may be using. It could range any thing from 1.5k to 3.5k or even more depending on the peel being used. Also the cost may vary in different citites. So its best that you see a qualified dermatologist near u and get the procedure done by him/her.