It’s a party that still has no price tag. This past week, New Jersey put up a $1.1 million down payment on the 2026 World Cup toward the cost of preparing MetLife Stadium for its role in the global sporting event — a planned $14.2 million makeover of the field for soccer play that organizers hope will ultimately be paid for by sponsors. But just how much the World Cup will cost the region remains a game in progress. And if those sponsorships do not materialize — or come up short of expectations — the state could end up footing more of the bill, officials acknowledge, as the state and the city …