Where and If Statements Laravel Eloquent

Very similar to this: Method Chaining based on condition

You are not storing each query chains.

$query = Scrapper::query();

if (Input::has('cat-id')) {
    $query = $query->where('cat_id', '=', Input::get('cat-id'));
}
if (Input::has('band')) {
    $query = $query->whereBetween('price', [$high, $low]);
}
if (Input::has('search')) {
    $query = $query->where('title', 'LIKE', '%' . Input::get($search) .'%');
}

// Get the results
// After this call, it is now an Eloquent model
$scrapper = $query->get();

var_dump($scrapper);

Old question but new logic :)

You can use Eloquent when() conditional method:

Scrapper::query()
    ->when(Input::has('cat-id'), function ($query) {
        $query->where('cat_id', Input::get('cat-id'));
    })
    ->when(Input::has('band'), function ($query) use ($hight, $low) {
        $query->whereBetween('price', [$high, $low]);
    })
    ->when(Input::has('search'), function ($query) {
        $query->where('title', 'LIKE', '%' . Input::get('search') .'%');
    })
    ->get();

More information at https://laravel.com/docs/5.5/queries#conditional-clauses