It depends on how good you really are.

I know of some ecommerce consultants that charge as low as $50 per hour, while some of the better ones charge $250 per hour. The more services you offer, the higher the rate you can charge.

The thing to remember is to never set your charges too low. It is MUCH HARDER to raise your rates when you feel you are undervaluing your services, compared to cutting your rates when nobody’s biting.