For David W. Page, the sharp increase in gasoline prices is more than an inconvenience. It could mean the end of a dream.

Page runs a small Falls Church agency that uses 26 vans to transport 500 retarded persons to and from jobs and therapeutic programs in Fairfax and Arlington.

With gasoline prices already averaging $1.13 a gallon in Washington and headed toward $2 a gallon by year-end according to some analysts, Page suddenly needs $50,000 -- or more -- to keep his program going.

He doesn't know if he is going to get it. Ultimately, the money comes from the state and the counties. But like other governments, businesses and people all over the country, they are already strapped by energy costs that are rising fantastically.

Page's is just one more small program. But he thinks it is an important one -- that means retarded persons can lead more normal, active lives.

"Retarded people have the same feelings as you or I, they want to love and laugh and cry and work . . ." says Page.

But the energy crunch may have a big impact on the way they do that.

Page's organization is called the Northern Virginia Association for Retarded Citizens. It is the local arm of a national outfit, and Page runs its transportation branch here.

A psychologist and family counselor by profession, Page is a soft-spoken man who sought out this "humanitarian" line of work after suffering a traumatic combat experience while a soldier in Vietnam.

Suddenly, however, he finds himself wrestling with price statistics and financial analyses. He is constructing graphs and flow-charts that he hopes will convince his financial angels -- ultimately government officials -- that his program deserves more gasoline money.

"We started this project to help retarded citizens live a more normal life," Page said. "I'm not sure we're succeeding, and to a large extent this is because of the cost of gas. I've looked at repair costs, insurance costs (and other costs), and a few things are actually going down in price."

He said insurance, for example, is less expensive for his program now than it was recently -- although this is not the case for many others who purchase insurance.

The transportation program works this way:

Page's vans fan out around the counties, following certain routes to pick up their riders -- usually at home. Then the vans leave the riders at work places and therapy centers. Last year, they made 68,000 trips.

The trips have been costing $3.25 per person. When the van returns people home later, that's another $3.25 -- a total of $6.50 a day that is usually charged to the particular state or county program that the rider is enrollled in.

But now Page says he's got to raise the price to $4.60 a trip -- or $9.20 for the round-trip that most riders make daily.

This price is so high that it brings the latent taxpayer in Page into conflict with the do-gooder. "As a taxpayer, I do feel very strongly about limiting the cost of government," he said.

But he hasn't resolved the problem. He merely muses: "We'd be one of the first things cut . . ."

A Fairfax County government spokesman said yesterday that steps were taken during the last few days to bring the county's "energy reserve" funds up to $4.1 million -- and Page hopes that some of these additional funds will come his way.

Meanwhile, Page is trying to cut the cost of the program. Tuning engines for better mileage. Cutting engine idling time. Trimming routes. He figures to cut fuel consumption by 10 percent by these and other means.

But when do you trim a route to the point of cutting some people off -- people who live far out so that to pick them up becomes "diseconomic" or "inefficient," as the economists say?

Page isn't to that point yet and doesn't know what he is going to do when he gets there. It is the great quandary of America's energy crunch. Listen to Page:

"I've been analyzing cutting the routes. One route costs us $11.21 per ride. I said to myself, 'That's inefficient. We've got to do something about it." So I looked into it.

"There's only three people on that route. It's a huge van that could hold 15 people, but it's specially adapted for wheelchairs and these three people are all in wheelchairs. One of them has to lie flat on his and it's extra-big. We couldn't squeeze another person in that van if we used a crowbar.

"Now, do I cut that route because it will reduce our overall unit cost?"

Page paused. Then he said softly:

"I'd rather take the money out of my own pocket . . ."