For the price of $1.5 billion and his Australian citizenship, Rupert Murdoch's bold acquisition of Metromedia's television stations is a move that seems to neatly position him to create networks on three continents.

Murdoch's 50 percent stake in Twentieth Century Fox -- with partner Marvin Davis -- gives his company a unique position as a producer of movie and video programming.

With two television stations in Australia and a satellite superstation beaming programs to cable television systems throughout Europe, Murdoch appears to be the media mogul who has all the pieces of a puzzle that could be assembled into a global television network. At the very least, he has acquired the potential to be the most important new force in American television broadcasting.

Yet media watchers from Hollywood to Madison Avenue, who view Murdoch with a curious mix of fascination and concern, raise two related and troublesome questions about his latest purchase: Did Murdoch pay too much? And can he create a fourth network in this country, wringing some profitable synergies between his Fox production capabilities and his television stations both here and abroad?

"It's a very, very pricey deal," says one Hollywood executive who asked not to be identified. "It's tough to get any real world numbers for justification of the deal. The size of the deal must presume that a very significant premium has been paid -- implicitly for the potential as well as explicitly for the cash flow.

"The potential is mainly the chance to build a fourth network -- which is a nice idea on the blackboard, but he'd have to make a significant additional commitment requiring a lot more deficit spending.

"It is a very defensible acquisition for strategic reasons, but on economic terms . . . no matter what numbers you use, you can't figure out how this whole thing hangs together."

In an interview, Murdoch dismissed the idea that he and partner Davis paid too much for Metromedia's television properties in cities such as New York, Los Angeles and Chicago, the nation's three largest markets. "When one considers the markets, I don't think the price was expensive at all," said Murdoch. "There just had to be a premium. But remember that we got some of the biggest markets in the world in one swoop."

However, many analysts and industry participants point out that the premiums now being paid for television stations -- particularly Metromedia's -- far outstrip historic premiums. In the past, television stations have sold for multiples of roughly 10 times cash annually generated by the station. In stark contrast, Murdoch and Davis paid about 16 times cash flow for Metromedia.

"Multiples have certainly gone up, and they've gone up for a reason," said one investment banker, "Supply and demand -- that's the whole ball game."

An increasing number of wealthy potential buyers for a relatively fixed number of television stations, say investment bankers, has dramatically raised station prices all across the board. Indeed, the Tribune Co. announced last week that it would pay a record $510 million to acquire KTLA-TV, the largest independent television station in Los Angeles. Hearst Corp. paid $450 million to the Davis/Murdoch group to acquire the former Metromedia Boston station. Analysts consider prices for those stations extremely high.

But industry participants argue that the supply and demand factor has done more than bring television property values more in line with their real financial worth -- it apparently has created a speculative bubble that may have unrealistically distorted their value upward.

"Murdoch paid two-thirds of what Capital Cities paid for a network ABC that was already in place," said one former network executive now active in independent production. "In my estimation, they probably made a bad buy."

The executive argues that television station values also have been artificially inflated by an unusually high surge in advertising over the past five years.

"The video games boom, home computers and the breakup of AT&T all generated lots of new television ads that just weren't there before," he asserts. "This has artificially inflated advertising rates," which, in turn, inflate station values.

"You have to think that there will constantly be new businesses emerging that will be able to launch major television advertising campaigns if you think that ads rates will continue to climb as they have in the past," this executive said.

Al Masini of Telerep, a New York company that coproduces and distributes such shows as "Entertainment Tonight" and "Lifestyles of the Rich and Famous" to television stations, agrees, adding that "there are more stations splitting the advertising pie in each city." He said the number of non-network television advertising dollars isn't rising nearly as fast as it has been in the past.

This advertising softness, combined with the incremental but growing impact of cable television and videocassette recorders on prime-time viewing levels, has led many industry observers to conclude that the major justification for the Metromedia price tag rests more on ego than on economics.

"Murdoch is the guy who is running the New York Post at a $10 million a year loss because he wants to have a newspaper in New York," said the former television executive.

"I think they paid a lot of money," said Robert Bennett, who had been president of Metromedia Television before the takeover. "I think there is an amount of gamble involved. I'm not sure they know yet what they're going to do . . . but I think they could grow like a rocket."

Barry Diller, who runs Fox studio for Murdoch and Davis, argues that the economies of scale and scope are there to transform Metromedia/Fox into a powerful, profitable enterprise without creating a fourth network to rival the big three.

"I think the phrase fourth network is irrelevant," he said, "What you want to see is a level of networking that has growth taking it from occasional to frequent."

In effect, Diller is talking about the growth of so-called ad hoc networks where a sufficient number of independent stations air first-run programs that justify national advertiser support. As head of Gulf & Western Industries' Paramount Pictures, Diller was instrumental in moving that studio's television arm into ad hoc networking.

"Take a show like 'Entertainment Tonight,' " said Diller. "If you look at the profitability of that on the stations on which it runs and the networking of it, you are talking about a considerable sum of money equal to the cash flow for an entire year of any television station in the top ten in the United States."

What Diller will not detail is when the Fox/Metromedia combo will undertake such networking efforts, as well as at what level and at what cost. He does assert that the company will be quick to form alliances with sports leagues and independent producers or major advertisers if that's what it takes to capture viewers and advertising dollars.

"It's not developing the programs that's the problem," said Telerep's Masini, "it's developing the distribution structure that's the problem."

Masini points out that non-network television stations effectively cover only two-thirds of the country -- and that, all things being equal, it is expensive for the cost of a network-quality show to be spread over two-thirds of the country rather than all of it.

But nobody doubts that the Metromedia/Fox nexus forms the nucleus for what could evolve into a fourth network structure if the number of independent television stations continues to grow.

"They now have New York, they have Los Angeles, they have Chicago," said Bennett. "They also have significant production abilities and Barry Diller who, I think, is a brilliant programmer."

Whether all these programming pieces can be assembled into a profitable network picture will determine whether Murdoch's most expensive gamble is also his most successful.