Mercedes could leave F3
Mercedes motorsport boss Norbert Haug says they use F3 primarily to develop links with young drivers and that they would quit the series if it became a "money wasting machine".
"It's a joke, F3 is not F1," he told Autosport. "I can't change the rules but I will accept it as long as we don't have to develop engines. As soon as F3 becomes a money-throwing competition, we will not take part.
"It's better to invest in young drivers than to invest in an F3 engine testing team. We've done a lot for guys like Lewis (Hamilton), Jamie (Green), and Paul (Di Resta) and our system is working well.
"We have the perfect system because F3 doesn't cost us anything – we get the money we spend back from leasing the engines."
But Volkswagen motorsport boss Kris Nissen doesn't believe their rivalry with Mercedes will have a significant effect on costs.
"It's not only about the money you're willing to spend," he told autosport.com, "you need to have the right people to do the job. I don't think there will be a problem with it getting more expensive because the regulations are very tight.
"You have to keep the rules stable for as long as possible, this is what helps to reduce costs. Also, the engine is not the main cost in F3 and it is possible to reduce budgets in other ways – you could use the chassis for longer or only have one choice of gearbox."