You, too, can foot the bill for a fine footloose fling

THAT once-in-a-lifetime trip! Well, maybe once every 20 years or so.

You've been saving for years, or just come into a lot of money, and you decide this is it. Although you may not see the overseas bargains that were available during the winter and spring, when the dollar was king, the United States currency is still ``surprisingly strong,'' says Jonathan Marcus, manager of Deak-Perera Boston Inc. And the British pound may come down again soon.

So before your nest egg or windfall drains away on replacing the hot water heater or repairing the old jalopy, take your trip now. When you make your plans, though, think about prices and bargains. If you can have just as much fun on less money, it might make the Big Trip more possible now.

One such excursion might involve tracking gorillas through the jungles of Kenya. If the idea appeals to you, think first of several hours of walking every day, says James Hyatt, president of Air & Marine Travel, in New York. (But for those who are game for this unique adventure he offers a warning: ``Never point. Gorillas do not like it.'')

Although some options, like the gorilla tracking, can be arduous, Mr. Hyatt says, you can have your own tent with toilet and shower, and all cooking is done for you. On these safaris, if a staff member spots an elephant in the middle of the night he will ring a bell to alert you to come to see it.

The wild-game parks are the big attraction in Africa. In Ngorongoro crater in Tanzania, zebras, wildebeest, gazelles, rhinos, and lions crowd around the watering holes.

Flying instead of busing between the main encampments in Africa is really worth the extra money, Hyatt says ($1,774 vs. $1,286 for a five-day African package). Gazing at the dusty landscape for eight hours at a time can get a little old, he adds.

Costs of the safaris average $250 to $280 a day per person in Kenya. Tanzania is about $100 more per day. Gorilla tracking (once you are over there) costs $1,400. The round-rip air fare from New York to Kenya adds $1,100 to $1,456 per person ($4,000 for first class).

Or why not ``do'' Europe?

Explore the thatched-roof villages in the English Cotswolds, reside at stately British country homes, and enjoy the luxury of riding the Orient Express from London to Paris. A grand tour of Europe can cost $150 to $200 a day per couple. Add the price of car rental ($24 a day) and the $650 round-trip flight over from New York (set up 21 days in advance) per person.

Although European meals can range up to $80 to $120 per couple daily at two- or three-star restaurants, you can find scrumptious dinners for $10 to $20 in little out-of-the-way places in Paris. Food costs in Europe are very similar to those in Boston and New York, Hyatt says.

To see Asia, he recommends taking at least 36 days. Round-trip air fares from Boston average $2,700 to $3,000 (less from the West Coast), with hotels and meals adding $5,800 per person.

In China, Hyatt prefers the American-style hotels now being built, because, he says, Chinese-run hotels often have poor service and are not as clean. He cites the Chinese cities of Pekiong, Xian, and Guilin as definitely worth seeing.

Visiting temples and markets in Thailand, taking in the world-famous dancers and beaches in Bali, and touring Australia, Tahiti, and Bora Bora (which Hyatt believes boasts the most romantic hotel) round out the trip.

Some of the gentlest and most self-sufficient people can be found in the Himalayas, says Carla Herwitz, of Overseas Adventure Travel in Cambridge, Mass. She suggests an 18- to 32-day trek through the highest mountains in the world. This can include six days of low-altitude trekking, up to two weeks for high-altitude trekking, and it can be strenuous. Visit small to large villages and Katmandu, the capital city. A ballpark figure for land, air, and most food costs is $2,500 to $3,500.

If you have a lot of time (100 days or more) and more money, there's always the trip around the world. Costs for an ocean liner range from $20,400 to $84,900 per person, double occupancy, depending on whether you want to travel in a closet deep in the hold or in an outside room with a porthole, says Hyatt.