A 75 cent lunch may sound like a bargain to most people, but it apparently is not enough to lure students at T.C. Williams High School away from the famous golden arches of McDonald's or the "howdy partner" at Roy Rogers.

The Alexandria school boad recently proposed raising the cost of school lunches for the second time this year -- from 65 to 75 cents. The proposal irritates at least one school board member, William B. Euille, who believes the price hike will drive more high school students out of the cafeteria lines and into the nearby fast-food restaurants.

At T.C. Williams High School, where students at the open campus are allowed to leave school grounds any time they don't have a scheduled class, cafeteria food, even at bargain prices, seems to be losing out. According to school figures, only 27 percent of the 2,600 students at Williams eat in the cafeteria.

Consider the eating habits of Tom Lacey, an 18-year-old senior at Williams and a member of the crew team. Nearly every day, Lacey heads for McDonald's or one of the other fast-food restaurants such as Mabel's Pizza or Lee's Delicatessan.

"The lines in the cafeteria are too long," say Lacey. "The food is horrible and there is just not enough to fill me up."

So Lacey spends $2 for a quarterpound cheeseburger, a small order of french fries and a coke. At Roy Rogers, the same meal retails for $2.07.

But for the current price of 65 cents, the same bill of fare is available in the school cafeteria about once a week, with a choice of two vegetables and milk instead of a soft drink.

While Lacey says he spends an average of $10 to $12 a week at the local delicatessens and fast-food restaurants, a week of cafeteria food costs about $3.75.

The cafeteria price includes a 10-cent deposit on food trays, which is refunded when the trays are returned. Some students say the deposit has encouraged others to freeload by collecting seven or eight trays and turning them in for the deposits.

While Lacey says he favors the price increase "as long as they improve the quality of the food or give us more," sophomore Leslie Hamilton is against it. "They don't give us that much now, and we are growing kids. I don't think that is right."

Another critic, sophomore Patrice Hofferman, says, "The pizza (stinks) and the grilled-cheese is disgusting. The only thing that is any good is the salad bar."

Donald Miller, director of the city school system's food services, says he is aware of the students' complaints. Miller has even started tasting parties where students can sample new dishes.

Miller says the price increase is needed because of 14 percent increase in the cost of the school lunch program.

"I don't want to raise the prices," he said, "But the cost of the meal is more than we are getting back."

The average cafeteria lunch costs $1.30, according to Miller, who added that the school lunch program would go broke without heavy subsidies from the U.S. Department of Agriculture.

Students from low-income families receive their lunces free or pay 10 cents. Depending on how much the students pay, the school is reimbursed anywhere from 17 to 97 cents by federal subsidies. Even so, Miller said he anticipates a $125,000 loss this school year on a $1.6 million budget.

Miller wants to change much of the Alexandria school lunch program, particularly at T.C. Williams, where the kitchen prepares lunches for five elementary schools in addition to the 600 it fixes for Williams students. "In the future we hope to have all on-site kitchens," he said. That would spare him the cost of transporting hundreds of lunches across the city every day.

If the school board approves the higher price at its March 19 meeting, the increase will be effective on the first day of the 1980-81 school year.