The cost of mole removal will be different depending on who you see. Here in Ottawa Canada, I use radio-frequency to remove these. Basically, this means that I use a device to heat the skin and burn the top layer of the mole. This flattens the mole but does not remove it. The problem with moles, is often, you can not remove the entire mole as you will trade a mole for a scar. So you need to be very carefull.
The cost really depends on where you live. It can range anywhere from 100-500$ I would assume.