MARBLEHEAD-Unlike Swampscott, Marblehead isn?t looking to establish a purchasing relationship with Lynn at the present time.Superintendent of Schools Paul Dulac said Friday that Marblehead has worked with Lynn to get a lower price on Number 4 heating oil in the past, but isn?t able to do that right now.?In the past we collaborated with Lynn to buy Number 4 heating oil,” Dulac said, noting that Number 4 oil is less often used today because it?s only used for older buildings.?None of the oil people are accepting group bids right now,” he said. “Things are too volatile. It?s not just Lynn, it?s for anybody.”Heating oil has been a difficult budget item in the past two years, and sharp increases in the cost of oil have suppliers waiting to see what the price will have to be this winter.In June, former School Business Manager David Keniston predicted a possible $250,000 deficit in next year?s school budget, based on then-current oil prices n and that was beyond the amount covered by the town?s oil reserve account.Keniston told the School Committee that the price of oil had the potential to increase 50-90 percent during Fiscal 2009.Last year?s oil costs were $1.04 million. A 10 percent increase in that figure would add $100,000 to the budget. Keniston and Dulac said the only course of action open to the schools is to further regulate the use of oil, such as closing schools in the evening to minimize school heating costs.However, experts are predicting a decrease in oil prices this summer.