Forget all those stories about how impossible it is to buy a house these days: "This is the best time of all," says real-estate whiz Robert G. Allen.

If high costs, soaring interest rates and scarce mortgage money are scaring you out of the market, Allen says you should try "creative financing." Along with a healthy dose of aggressiveness.

You may even be able to buy your new home "with little or no money down."

"Send me to any city in the United States," challenges Allen. "Take away my wallet. Give me $100 for living expenses, and in 72 hours I'll buy you an excellent piece of real estate using none of my own money."

Starting almost from scratch three years ago, Allen, now 31, parlayed a passion to be his own boss by buying and selling homes and apartment buildings. He now estimates his net worth at almost $1 million.

Not that he didn't make a few mistakes along the way. "What a dumbo I was," he says, recalling the time he bought a very long, very narrow lot -- shaped like "a needle, good for a pilot who wanted his own landing strip in the back yard."

But, he adds, "Real estate is the most forgiving of all investments -- you usually can redeem it."

Allen has put his experiences into a self-help book: "Nothing Down: A proven program that shows you how to buy real estate with little or NO money down" (Simon and Schuster, 255 pages, $10.65). On most weekends, he spreads his message around the country in two-day seminars, charging $395 per person. In Washington this week, he gave three (free) 90-minute lectures.

The reason, he says, that now is a good time for buying a house is that it's a buyer's market. Owners are having a hard time selling their homes through traditional methods. He opts for the unorthodox.

With interest rates approaching 17 percent, Allen says, "Stay away from banks, savings and loans and mortgage companies." Stick, he advises, to the "area of seller financing."

To illustrate, he jumps from his chair and pulls from his briefcase a page of D.C. classified ads. He points to house-for-sale ads he's circled in red:

"8 percent owner financing."

"Flexible owner financing."

"Owner-assisted financing."

"Owner will take financing."

"Don't tell me it's not there," he says about the possibility of finding a house available for less interest than today's paralyzing market rate. "In one page I've circled 23 properties. It's like this in every city."

In such a situation, you may -- for example -- assume the owner's original mortgage at 8 or 10 percent and then negotiate for a second mortgage from him at as high as 14 percent. "So what? At least it's not 17 percent on the entire amount."

To find the real bargains, says Allen, seek out the "don't wanters," the homeowners who, despite market conditions, have to put their property up for sale. Families being transferred out of state are a good prospect. They are likely to be more "flexible" in the kind of no-money-down deal you might work out with them.

"If a guy is moving, he's got to sell. He has no choice," says Allen.

There are "lots of don't-wanters: Look for clues in the ads. They're a collection of cries for help."

Such hints often can be found by searching the houses-for-rent-or-lease columns, he says. "Look for the word 'option' -- lease with option to buy." That could be the sign of a person who is "under pressure to sell" and is looking for rental income until he or she can find a buyer.

But, warns Allen, "That seller is not stupid. It's naive to think you'll take advantage of him willfully. Use the Win/Win philosophy.

"Start right off saying, 'Mr. Seller, you've got a problem. I've got a problem, too. This is all I can afford to offer, but it may be the solution to your problem.'" Both sides, he says, can end up winners.

If, under Allen's program, you've found below-market-rate mortgage money and a potential bargain from somebody who wants to sell in a hurry, the next step is to swing the deal with as little of your own money as possible.

Some of Allen's techniques may seem farfetched, but he insists they have worked.

One of the first things he does is ask the homeowner why he is selling. That gives an idea for the kind of creative financing that might be arranged.

One man told Allen he needed at least $2,000 in cash to buy furniture for his new home. "I've got a Sears' card," Allen told the seller. "You pick out what you want." Instead of putting up $2,000 for the property, Allen charged the man's purchases on his credit card, paying them off later in installments.

One woman was eager to sell because she wanted to pay off $11,000 in debts. She said she needed at least that much cash from Allen. Instead of paying her the $11,000, he assumed the loans, paying them off at the rate of $350 a month.

What if, for example, the seller wants to put the downpayment into savings? Suggest he might be better off accepting a higher price from you instead. "You wanted $85,000 for the property," Allen tells an imaginary homeowner. "I'll pay $87,000 with nothing down. Raise the price, lower the tariff."

If you're a sharp negotiator, you might convince the seller's real-estate agent to make you the loan of his commission "or I won't buy at all." Instead of putting up $5,000 in cash so the seller can pay off the agent, he suggests you give the agent a note for $5,500. s

"An agent in times like this who doesn't understand creative financing is starving."

Born in Alberta, Canada, Allen now lives with his wife and daughter in Provo, Utah. He spent two years as a Mormon missionary in Tahiti before getting a master's degree in business from Brigham Young University in 1974. g

At that point his accountant father, to whom he has dedicated his book, gave him a small start. His first ventures into real estate convinced him he needed to learn more. So he spent six months and $6,000 attending 14 real-estate seminars around the country. He's got his million since.

As testimony to his belief in real estate as a continuing good investment, he and a partner are considering buying in the near future 100 homes in about 10 cities.

For the confused home hunter, frightened out of the market by what he reads and hears, Allen urges his "optimistic/aggressive" approach. He also advises putting time into the search, cautioning that it won't be easy.

Ninety percent of sellers are not "don't wanters," he says. "But I'm very thick-skinned. I'm willing to accept 50 no's to get one yes."

"I can't believe how many people roll over and play dead. If they want a house and they see the way house prices are going, why aren't they out buying?" h