The European Commission is aiming for EU countries to start buying gas jointly "well before summer", in a bid to help countries refill their storage and avoid a supply crunch next winter, European Commission Vice-President Maros Sefcovic has told Reuters. The EC hopes that the scheme will help Europe refill depleted storage caverns and also negotiate lower prices by using countries' collective buying power. Although Europe has managed to fill its gas stores ahead of winter, it has paid a heavy price: the cost of replenishing natural gas stocks…