Ever wonder how Gerald Ford can afford to build a $1 million ski chalet in Vail, Colo.? Or how Henry Kissinger pays a retinue of staffers? Both work hard at the lucrative sideline of giving speeches to organizations that want to impress their membership at annual meetings by presenting an ex-president or former secretary of state.

In a memo to "our VIP clients" cawing about how many of its speakers have appeared on ABC's new "This Week with David Brinkley," lecture agency mogul Harry Walker listed some recent as well as upcoming appearances by Ford and Kissinger. And by the description of some of the events, it seems clear that if the money is right, celebrities will talk to anybody.

Kissinger recently knocked them dead at the National Tire Dealers and Retreaders Association meeting in Dallas and next month talks up the Potato Chip/Snack Food Assocation in Las Vegas.

In either a typographical error or an unconscious slip of the mind, Walker labels Ford "probably the most after personality in America." That probably means "sought after," since Ford's schedule includes at least three appearances a month. Last week he addressed the Formica Corporation in Miami Beach. Coming up are speeches before the Angelina County Chamber of Commerce in Lufkin, Tex., the Sunbeam Corporation in Chicago and the Automotive Service Industry Association in Las Vegas.

Footnote: Speakers such as Ford and Kissinger normally command $10,000 or more for an hour's appearance. One notch down are veteran media celebrities such as Time's Hugh Sidey and relative newcomers such as ABC's Ted Koppel. Since the success of his late-night news show, Koppel has been asking $7,500 per appearance. And, notes another of Walker's memos, Koppel prefers weekend gigs.