At a radio and television store in suburban Prince George's County the other night, a young couple stood intently before a color television set, their eyes darting back and forth from the set's screen in the small machine sitting on top of it.

A salesman moved a knob here, pressed a button there, and talked - talked and talked. More than once he moved down the aisle to another TV set with another small machine sitting on top, and the couple moved with him. Images appeared and reappeared on the screens before them, sometimes the same image two or three times.

After about two hours, Danny and Linda Hill of Oxon, Md., made their decision: They bought a Quasar "Great Time Machine" video tape recorder (VTR) Price: $995.

Hill, a house Painter whose paint-flecked hair suggested he had come straight from work, had a lot of reasons for wanting the new gadget. "A lot of times when we're going to go out, there's a show on we're going to miss," he explained. "Or there are two good shows on at the same time. And I think a lot of the stuff I'll tape will be to occupy the kids (he has two), like cartoons."

"Really what it is is an expensive toy," sighed his wife.

Expensive toy it may be, but a lot of people in the Washington area are spending the money to get one these days - and not simply the wealthy. In the view of some manufacturers, Washington is emerging as one of the better markets for the product. So much so, in fact, that shortages of some brands have developed.

"The whole thing is exploding," says Jack Luskin, president of Luskin's Inc., a discount appliance chain. "It's the biggest thing since CB's took off. But this isn't just a craze item."

Manufacturers are reluctant to disclose their sales figures, but several area distributors say that VTRs are now selling at the rate of 1,000 a month locally for all brands.That compares to about 200 a month in the first eight months of the year.

What seems to be turning it into a mass-market item now, after 10 years of that prediction by manufacturers, is a combination of factors: a manufacturers' price war since the end of summer, the sudden availability of several brands, and a major advertising campaign that has raised consumers' awareness of the wonders of the VTR.

The result, say dealers and distributors, has been a new-product-seller's dream. "We sold 20 to 30 units before we even had any available," said Earl Onaran, president of Erol's Color TV. "We sold four before we even had a floor model."

Many stores can't get their hands on all they need, with some brands in shorter supply than others. And according to Herb Filderman, president of George's some people are "panicking" if they can't get their hands on a VTR right away.

"We've had bribes to sell the machine off the floor," he said. "It's like Gucci bags. Everyone wants one if they can't get it. And people are afraid if they don't get it immediately, they may not get it at all."

Some distributors are having their problems too. "I owe out hundreds of unkts to the dealers at this point," moaned Howard Rendelman, Baltimore-Washington distributor for Quasar.

"I was just on the phone to Chicago (Quasar's headquarters) begging for units to the dealers at this point," clear. They're promising me some for next week, and right now they're scouting the country for me trying to meet my orders."

In some parts of the country, Rendelman explained, "it hasn't taken off yet as big as it has here."

Indeed, confirms a Sony spokesman, Washington appears to be one of the better markets for the VTR so far. Joseph Lagore, vice president of Sony's consumer products division in New York, attributes that to the general affluence and high educational level of Washingtonians.

"It's also a very media-conscious city," he notes. "You have a lot of high-powered men and women who don't want to be at the mercy of network programming time. With a timer, or having someone else do it, they can record material off the air for later viewing."

Most of the people buying VTRs these days, says Lagore, are in the $18,000-and-up income bracket. It's not like the early days of a few years back, he adds, when only the most affluent were buying it.

Jack Luskin of Luskin's confirms those impressions. The "mainstream" of the VTR-buying public in Washington, he says, is "the guy or girl 25 to 40 who's been brought up on a whole lifetime of television. Now they're working and have the wherewithal to afford what they want but aren't able to sit down all the time and see what they want when they want. And the husband may want to see one thing, the woman another. This way everyone's happy."

Most VTR users intend to use the devices only for this sort of "time transfer," retailers say. One dealer reports selling to a Washington Red-skins playtr who planned to use the VTR to catch each football game he was in.

Some consumers also seem attracted by the chance to build their own library of movies and major TV events - although whether or not they have the right to de so under current copyright law, however, is still in question.

And then there's what several industry sources believe will be one of the largest uses of VTRs within a few years: making homemovies, including pornography. But that, they say, has to wait for wider consumer acceptance of the product (the VTR, that is), and a decline in the price of the color camera (now $1,500 and up) bought as an accesory.

Many people who want cameras want them for pornography, says one retailer. "But if they want it for pornography, they don't want it in black and white - they want color."

A spokesman for one of the major manufacturers agree, saying , "It may do for home movies what Polaroid did for home photography. After all, with this, people don't have to take film in to be developed. Whatever the camera records, it plays back."

Not everyone is buying the VTR to use at home, though, Several Washington dealers report selling units to a man who claimed he was going to take them to Brazil and sell them at a modest markup - about $4,000 each. The undertaking, he figured, would net him his round-trip fare, hotel bills, and all the spending money he could possibly want.