March 27, 1983

For evidence that SoHo has become another high-priced Manhattan residential area, look at 426 West Broadway, just opened and billed as SoHo's first luxury residential condominium. The 35 units range in size from 550 to 3,000 square feet and are priced from $120,000 to $350,000.

A PROSPECTIVE Cuomo administration appointment has split the Island's Democratic delegation to the Legislature and produced a breach between the new Governor and one of his earliest supporters on the Island. The appointment, which would take effect May 1 or before, would put Harold D. Berger, a former Democratic district leader in Nassau, into the office of regional director of the Environmental Conservation Department - one of the most sensitive state posts affecting the Island. He would replace Donald J. Middleton, who held the post through the Carey administration and was originally sponsored for the job by Dominic J. Baranello, the Suffolk Democratic chairman. Controversy over the matter has been building up since it became known that Mr. Berger was the Governor's choice.

SINCE it's politically imprudent to raise taxes, elected officials from county executive and town supervisor on down to village trustee are turning to user fees as a means of bringing in new revenues. A user fee is a tax, though it doesn't sound like a tax. Proponents say that user fees are an effective means of making people pay for services that they alone use, such as golf courses and ice-skating rinks. Opponents argue that user fees are a form of double taxation that discriminates against the poor and elderly. Opponents also argue that the fees are being raised at all levels of government on the Island not just to cover the cost of a particular service, but to produce new tax revenues.

''It may not be a work of art,'' Representative Barber B. Conable Jr., a New York Republican, remarked. ''But it will save the nation's basic social insurance system from imminent disaster.'' So Congress, in last week's pre-recess rush for the exits, passed and sent to the White House legislation designed to keep Social Security solvent well into the next century. The plan, which draws heavily on the recommendations of a Presidential commission, would pump nearly $165 billion extra into the Government's retirement trust funds by the end of the decade. Starting next year, new Federal employees and those on the payroll of nonprofit organizations will be required to join; new payroll tax increases are due in 1984 and 1988; for the first time benefits paid to more affluent retirees will be taxed; and the retirement age will be gradually increased by two years, to 67, by 2027.

THE tax cost of operating an office in New York City is going up s harply, widening the differential between what it costs to house a b usiness in the city and in urban and suburban locations elsewhere i n the metropolitan region. Most businesses pay real-estate taxes indirectly as part of their rent, and taxes on office buildings in prime Manhattan locations add an average of $4 to $5 a square foot a year to commercial rents, double the average tax cost of $2 a square foot for equivalent space outside the city. In new buildings in the city, taxes cost tenants a minimum of $10 a square foot. In addition, office tenants in the city also pay a commercial rent tax of 5 to 6 percent a year on their rent bills, which can add about $2 a square foot more to their costs. These differentials have existed for many years, but now they are widening. Mayor Koch is proposing to raise the real-estate tax rate to close the gap in his 1984 budget. Until mid-March, he also planned a new 10 percent capital-gains tax on real-estate transactions of $1 million or more, which would fall principally on commercial properties. After Governor Cuomo proposed such a tax statewide, city officials said they would wait until the actual legislation was drafted to see whether they could combine their plan with the Governor's, scrap it or substantially alter it.