Magento will not take into the account the simple products’ price of a configurable one. Simple products’ prices are ignored. If you want to sell a simple product X having price $120 and a simple product B ($130) then set configurable product’s price to $120 and add products you want to associate with this configurable product. After adding them click on ‘Associated Products’ tab which opens a block named Super product attributes configuration, which contains options and price differences and set the prices accordingly as described in attached image.
Moreover there’s an extension that allows you to use simple product prices instead of price differences since it’s free extension. The extension is “Simple Configurable Products (SCP)”