The Washington Ballet's spring season, which opens next week at Lisner Auditorium, will revive the dollar-a-ticket policy that was a standing-room-only success last fall. It's not that the company wouldn't rather sell tickets for its advance, reserved-seat prices of $7.50 to $10, but it has decided that a filled cheap seat is better then an empty expensive one. The policy will continue, says director Al Miller, unitl "every program is sold out in advance." He believes the policy is building a new audience for full price tickets and that the dancers feel a "special electricity" when they know they are playing to a capacity crowd. Meanwhile, the company is not making enough on ticket sales to meet its expenses, but neither does any other professinal dance company in the world.

"Dollar-a-ticket" is a slightly simplified statement of the policy. Prices of the cheap tickets (which go on sale one hour before curtain time) range from $1 (week nights) through $2 (Saturday matinees) to $3 for Saturday and Sunday nights. Try to get those prices for a first-run movie.

Not all dance companies are keeping this busy. The Pennsylvania Ballet (which has been losing money on sold-out performances) has suspended production activities for three or four months to save money while it concentrates on fund-raising. So far, it has raised $1 million but needs another $1.5 million. The performance moratorium is not expected to affect the company's scheduled appearance at the Kennedy Center, May 4 through 9.