SOLID Principle In Laravel with Repository Pattern

If you're going ahead the way you've shown, i suggest you to use a single controller for your quotations and use a Factory design pattern to create your $quotation objects

For example, with a simple factory like this:

//FACTORY CLASS
abstract class QuotationFactory
{
    /** return QuotationInterface */
    public static function createQuotation($type)
    {
        switch($type)
        {
            CASE "private":
                return new PrivateQuotation();
            break;

            CASE "commercial":
                return new CommercialQuotation();
            break;    
        }
    }
}

you could use the factory from you controllers' methods:

//YOUR CONTROLLER'S METHOD
public function store(Resource $resource)
{   
    $inputs = $resource->all();

    //delegate objects creation to factory class
    $quotation = QuotationFactory::createQuotation( $inputs['type'] );

    $this->repo->save($inputs, $quotation);
}

This way you are not going to violate the open/closed principle in your controllers, because as you add quotations, you'll only need to modify the method of the factory (adding cases to the switch statement ), and it will return a QuotationFactory object wherever needed.

This will also keep your code DRY and SOLID because you don't have to repeat the if/else statements to create your objects in your controller's methods as you delegate the responsability of the objects' creation to a specific factory class

As correctly pointed ount in the comments below, the Simple factory is going to help you avoiding the Open/Closed Principle in your controllers but be ware that, from a more general point of view, the Simple Factory itself is inherently violating the OCP as it uses a switch case.

Anyway, from what i see of your application, the Simple factory could be a good solution, as your primary concern is to build in many places instances from a variable type. Thus, using the Simple factory you can 'hide' this process of creating objects into the factory and get the instances you need in your controllers. So you are violating the OCP only inside the factory in the switch case, but i think this could be a beareble trade-off