IN prosperous Hong Kong, one would like to think that $10 for an out-patient consultation fee is an easily paid sum for all of us. But in fact, it may be a lot of money for the less fortunate. Do we ever think of the plight of those low-income people, the poor elderly, and those who are in need of long-term medical treatment? It is to help such people, that the ''Free Medical Services Donation Scheme'' was launched. It aims at encouraging people from all walks of life to help out with an act of charity. The four-month scheme, running from July to October, is organised by the Tung Wah Group of Hospitals and Commercial Radio 1. The fund-raising activities included the charity premiere of the film The Bride with White Hair held in August. On another occasion, popular singer Sally Yeh donated part of the proceeds from her concert on August 2 to the hospital group's medical services. Around 15 prominent people, including singers like Hacken Lee and Vivian Chow attended a press conference recently to introduce the scheme. ''The hospital group and Commercial Radio 1 have co-organised the scheme for the fifth time to raise funds for maintaining the group's tradition of free medical services, the cost of which was estimated at $25 million for '93-'94,'' Mr Jackie Wong, chairman of Tung Wah, said. Mr Frederick Lui said preparations were underway for the Charity Tung Wah Day, another fund-raising programme, to be held on September 12. At the coming Charity Day, mooncakes will be sold at New Town Plaza Phase III, Sha Tin, from 10 am to 6 pm. Popular singers such as Hacken Lee, Vivian Chow as well as DJs from CR1 will be present. Maple Hui, one of the singers who will attend the moon cakes charity sale, told Young Post that the function was of great value to the poor patients. On the same day, charity boxes will be placed at a number of restaurants and food premises to collect funds. A Charity Dinner Show, the highlight of the scheme, will be be held on October 22 at the Hong Kong Convention and Exhibition Centre.