Thanks for the question, its hard to say exactly without seeing the lesion especially since it may be covered by insurance if there are medical concerns otherwise I would guess around $1000
It is certainly important to have the area evaluated by a dermatology provider who can screen it for malignancy. Your dermatologist can also give you reassurance if the mole is not suspicious. If your dermatologist is worried that there are certain features in the mole that make it suspicious for melanoma, they may recommended surgical removal in order to have it examined by a pathologist. This would be done for medical reasons and should be submitted to your insurance company. If the dermatologist feels there is no medical reson for excision, then many offices may have prices they can give you for treatment for cosmetic purposes.