As a licensed contractor I think you need to take responsibility rather than blame someone for your mistake. EG: you should get 3 bid before selecting a contractor. Also, It is rude to try to negotiate after the work is done, even if his prices are high. It is tough enough to be a legitamate company, with insurance and workmans comp. So, when compairing prices you also need to compair crudentials and insurances. Electrical done wrong can KILL or set your house on fire! With that kind of liability, you should expect to pay extra.