With the cost of almost everything going up, there's still one bargain: education. Federal, state and local governments, plus thousands of nonprofit senior centers, are offering low-cost or no-cost courses to elderly students. Money is available, and these organizations are looking for expanding enrollment.

You might say you're too old to go back to school. Nonsense. We should keep learning until the day we die. Most courses for the elderly as held in a relaxed atmosphere where students can go at their own pace. Some centers and government agencies even provide transportation. Organizations such as the American Red Cross, YMCA, YWCA and Kiwanis not only offer special courses, they provide volunteer drivers for needy students.

Where do you fing special courses for the elderly? The National Council on the Aging recently published a list of all sorts of places providing intriguing and ecriching courses.

For example, one Midwest senior center offers basketry, calligraphy, ceramics, contemporary furciture design, creative writing, drama, tai chi, exercise, French, Spanish, guitar, jewelery making, knitting, leather tooling, embroidery, macrame, oil painting, sewing, pool lessons and weaving.

Other centers offer courses that provide practical information such as health care, cooking for one, managing personal finances and auto maintenance.

Communities are finding they have a wealth of potential teachers for these courses. They can use retired teachers, professionals in various fields and people who know a lot about any given subject.

To find out if your community has special courses for senior citizens, call your local government agency that deals with aging. Your school district or department of education should have a rundown of continuing education courses. Community colleges are a good bet, too. Some offer a wide variety of courses at very reasonable rates.

Your county or city department of agriculture extension service is another possibility. Often you can find home economists offering courses in consumer purchases, home remodeling, gardening and cooking.

If there's a public radio or TV station in your area, you might find special courses being aired this summer. This way you can listen to the course and do the work at home.

According to the National council on the Aging report, a number of state governments supply special grant money to find courses for the elderly-Oregon, for example, gave money to the Campbell Senior Center in Eugene to set up a course in contemporary furniture design.

In Biloxi, the Mississippi Council for the Arts and Humanities is providing money for a circuit rider who leads discussions in rural areas.

Q: Some stores are asking for my address and telephone number when I buy things with my bank credit card. Isn's this and invasion of my privacy?

A: Yes it is. Most banks do not require a phone number on a credit card receipt, but some merchant are asking for this additional information because they feel it gives them added protection when the amount of the sale isn't enough to phone in for credit verification. In some cases the merchant wants the information simply for his mailing list.

Next time you're asked, advise the merchant you're not required to divulge your phone number and see what happens. If the sales clerk wants the sale, he probably will waive the requirement. If not you'll have to decide whether to take your business elsewhere or grudgingly give your phone number and be done with it.

Q: Your column on flight insurance was right to the point. But I hope your readers weren't misled into thinking they get $150,000 travel insurance for $3 a year.

Each American Express cardmember who orders it gets the insurance coverage (on top of $25,000 automatic coverage) for $3, which is added on to each trip billing where the card is used for payment. - J.G., American Express Company.

A: I said Amex members get the insurance for $3. I should have said $3 for each trip. Also, I've noticed that the amount is now $175,000 for $3 - $25,000 more than the old limit. This plus the $25,000 automatic insurance each member gets gives a total of $200,000 per trip.

Q: I used to be able to work on a seasonal job for three months and earn good, full-time paychecks. I could earn this money even though it put my annual wages above the limit set by Social Security for receiving benefit checks. They just didn't send checks for the months that were over the monthly limit. Now, I'm told, they allow obly a strict, annual wage limit. Is this true? - Mrs. A.C.R., Sebastopol, Calif.

A: I'm afraid so. You can no longer make extra money for several months on a seasonal job if it puts you over the annual limit of $4,000 ($3,240 if you're under 65).

Theis annual limit will go up $500 every year until it reaches $6,000 in 1982. Only during your first year of retirement can you use the monthly wage limit instead of the annual limit.