So we need to update all simple products prices and special prices by making them equal to their related configurable products, but we can't find any extension or process to do that all in one. We could do this one by one by hand but there are like 3000 products! Actually we change the prices in the configurable products but prices in the simple ones was the same when they was first added.
First of all, this is normally not necessary. Magento will always use the price of the configurable product and will ignore the price which is stored in the associated simple product. Hence, it does not really matter if the associated simple products have a wrong price.
But maybe you use an extension which changes this behaviour and which takes the prices of the associated simple products. Then you could just use the
Update Attributes feature in order to change the price. Therefore, you go to
Catalog - Manage Products, tick all the products in which you want to change the price (probably always one configurable product and the associated simple products), click
Actions - Update Attributes in the upper right corner of the table, click
Submit and update the prices in the following form.