The tolls are about $20 and you can EZ-Pass it I think until Maryland.
As far as the drive vs fly analysis, you also need to consider the wear and tear on the car...using the IRS mileage allowance of approx 36 cents per mile. at 1300 miles each way it's $470 each way. I was able to get Jet Blue flights out of JFK RT for $165 per person (4 of us), plus rental car for the 2 weeks for about $400, so for just about $1100 got the whole transportation thing sorted out. We stay at our DVC resort when we go so that's not really a current period cash flow issue.
For us, at the current price we decided to fly after driving for the past 2 years. It also gives us 2 more days in the parks.