As the conscience of America, - I have been giving a lot of time and thought to recent events surrounding Soviet defector Arkady Shevchenko and his parmour Judy Chavez.

While all the facts in the case have not been disclosed (we have to wait for Judy's and Arkady's books to get the rest of them), this much is agreed upon by everybody.

Shevchenko had a high position in the UN when he came over to our side. He met, or was given, as a reward. Miss Chavez, who worked for an "escort" service in Washington. He paid Miss Chavez $500 a night for her friendship, and spent between $35,000 and $40,000 on her for gifts and a trip to the Virgin Islands. He was known in the CIA as "The Spy Who Was Never Cold."

The facts that are in dispute are whether Mr. Shevchenko paid for Miss Chavez' services out of his own pocket or whether they were paid for by the CIA to keep him happy and talking. If Arkady spent his own money, he was taken advantage of for being a foreigner. But if the CIA paid for taxpayers have a right to ask some questions.

The first is: Why on earth was the CIA paying Miss Chavez $500 a night when the going rate in th eintelligence business for this sort of thing is $100? If Arkady was paying for it, why didn't someone in the FBI or CIA warn him that he was being overcharged for Miss Chavez' nightly companionship?

If the CIA is footing the bill, as Miss Chavez claims, it means there is a serious lack of cost control in the agency when it comes to providing escorts for Soviet defectors.

No loyal American would take issue with the fact that a high-ranking Soviet official, who wants to come over, should get anything he wants from the CIA in exchange for intelligence secrets.

But when you start paying outrageous prices for close encounters of this kind, you are not only contributing, as President Carter said at his press conference, to inflation but you are setting a precedent for other Soviet defectors, which the United States can ill afford.

The next defector will also expect a $500-a-night female companion, and if she is paid less he will feel that the CIA is not treating him with the same respect they did Arkady. How many "escorts" can our intelligence agency supply at these rates before it starts shortchanging our other spy operations?

Even if the CIA can afford it, other friendly intelligence organizations are furious about the publicity given to the Shevchencko-Chavez affairs.

"We've never paid our girls more than $50 a night," a French intelligence agent told me. "This puts every Western intelligence agency on the spot. The CIA has made the price of sex so high, we may not be able to use it any more as the ultimate weapon."

An Israeli agent thought Arkady was a KGB plant. "What better way to break the CIA budget than to have a defector demand a woman with expensive tastes, a yen for beautiful cars and a desire to make love in beautiful resorts. We could have put up a spy satellite for what it cost the Americans to keep Arkady talking."

Because of all the publicity, the CIA must now give Shevchenko a new cover and move him to a safer city than Washington.

I suggest Cleveland. It is not only a nice place to live, but the going rate there for an "escort" is $35 a night including taxi fare. Making Arkady live in Cleveland while they debriefed him would certainly save the CIA a lot of money.