However, when objects become too rare, they no longer register with most bidders and can be quite cheap. Although Shang ivory carvings of the 12th century B.C. from the Anyang site are virtually unobtainable (most are in museums), it only took $9,375 to get a magnificent fitting carved with a taotie mask. The experts themselves had underestimated its significance, as witness the unduly modest $3,000-5,000 estimate. Discussed in scholarly publications as early as the 1950s and exhibited at Columbia University in February 1965, the piece could go into any major museum.

I would have most readily succumbed to the lure of some Tang and Song ceramics. The rarest lot by far consisted of a wine ewer and a small globular jar offered together. Medallions molded separately and applied on both pointed to a date around the early 8th century A.D. Most important, these showed the two pieces to have been made as part of a set. Few sets ever reach the market as such, because the diggers break them up, and, if diggers do not, the dealers who handle them tend to sell them a piece at a time.

This set was exceptionally beautiful. The medallions covered in touches of green, ochre and ivory glaze stood out on the amber ground of the ewer and the deeper russet ground of the globular jar. The outline of the lobed medallions cusped at the top, and the riders — in flying gallop, hunting deer — were borrowed and reinterpreted from Sogdia, the ancient east Iranian land of Suguda, as it is called in the Persian Achaemenid inscriptions of the 6th century B.C., and later known to the Romans as Sogdiana. Centered on present-day Samarqand in what is now Uzbekistan, Sogdia was the great intermediary between East and West. Large Sogdian settlements within China played the lead role in the elaboration of a hybrid art of which the set is a remarkable example. The ewer acquired by Sackler from J. T. Tai & Co. "prior to 1975" had obviously reached the West before 1970 — few objects left China during the turmoil of the Cultural Revolution — and, by inference, the jar as well, although Sackler apparently bought the two objects separately and miraculously reunited them. At $21,250, just below the high estimate of $18,000 plus the 25 percent fee, the set was a steal.

Another rarity followed, and here bidders were more alert. A squat rounded pot of the 8th or early 9th century had an extremely unusual pattern simulating a bowl with a fitted cover in the form of a more shallow bowl turned upside down, a particularity that was not mentioned in the catalogue. On the cover a lotus chalice pattern, often found on the underside of bowls, emphasized the concept of a vessel turned upside down. It strongly contrasted with the motif of white flakes on green ground on the lower section of the jar, and, as if to make the division between the simulated cover and the lower section crystal clear, two deeply incised lines separated them at the transition. This jar too was included in the 1965 Columbia University exhibition, mentioned earlier. The estimate, $3,000 to $5,000, totally disregarded the rarity of the object, which ended up at $32,500. Even so, it was a great buy.

For collectors in search of the unique, nothing equaled a cizhou high-shouldered vase of the 14th century, with a short narrow neck of the type called meiping. Painted in sepia on ivory ground (the usual colors of cizhou wares), two groups of two standing figures facing each other, staffs in hand, stood out on the otherwise undecorated ground, framed on all sides by sepia bands. The figures were dashed off with a freedom heralding the brisk strokes of the so-called Individualist painters in the 17th century. No other vase with such tableaux, possibly inspired by murals, has been recorded. Arthur Sackler had bought the meiping in 1966 from the New York gallery Warren C. Cox Associates. Again the estimate, $3,000 to $5,000, bore no relationship to the importance of the vessel. At $11,875, it was a giveaway.

Not so the magnificent vase, also a meiping, that came next. The architecture of the shape, more fully rounded and much more powerful, was typical of Northern Song art at its greatest in the 11th or 12th century. The vigor of the form was matched by the extraordinary boldness of the carved pattern of huge peony blossoms and stylized leaves carried by curving stalks painted in sepia brown on the off-white ground. At $134,500, slightly more than the upper end of the estimate, this masterpiece from one of the greatest periods of Chinese ceramic art was worth every penny. I would have gladly run away with it.