how to approach refactoring interleaving logic?

I want to refactor this code to be clean and solid. Currently I'm a bit stuck how to do this.

Imagine a price calculation: (I simplified the code, I put the elseif just make it clearer)

class Prices {

    function generatePrices($dataSource1) {

        $dataSource2 = $dataSource1->getDataSource2();
        $cases = $dataSource2->getCases();

        foreach($cases as $case) {

            if($case->isCaseA()) {
                $fee1 = $dataSource2->getFee1();

                if($dataSource1->isCaseA_1()) {
                    $fee2 = $dataSource1->getFee('caseA_1');

                    if($dataSource1->isCase1()) {
                        return $fee1 + $fee2;
                    } elseif($dataSource1->isCase2) {
                        return $fee1 + $fee2 + $dataSource2->getFee3() + $dataSource2->getFee4();
                    }

                } elseif($dataSource1->isCaseA_2()) {
                    return $fee1 + $dataSource2->getFee('caseA_2') + $dataSource2->getFee4() + $dataSource2->getFee5();
                }

            } elseif($case->isCaseB()) {

                if($dataSource1->isCaseB_1()) {
                    $fee = $dataSource2->getFee('caseB_1');

                    if($dataSource1->isCase1) {
                        return $fee;

                    } elseif($dataSource1->isCase2) {
                        $return $fee + $dataSource1->getFee6();
                    }

                } elseif($dataSource1->isCaseB_2()) {
                    return $dataSource2->getFee('caseB_2') + $dataSource1->getFee6();
                }

            }
        }
    }
}

So I thought about making a Fee factory which gets all data sources. Depending on the case it will instantiate a concrete FeeCase class that then will return the appropriate fee. But I don't like how I have to pass all data sources. Yet if I would pass all data needed for all cases I'd have to pass like 10 or more variables.

Any input on this is highly welcome. I'd prefer a path to get to my own solution. But of course if you have a solution at hand I'm grateful about that too.