Gagosian Gallery's booth at Frieze, featuring sculptures by Jeff Koons.

One of the last preparations before doors opened to the Frieze Masters art fair was the installation of Richard Long's mud painting at London's Lisson Gallery. The mud is applied directly to the wall, and the floor needs to be covered with a protective sheet. When the work is finished, there is a clean black line along the bottom of the wall that draws the eye. In an environment where everything is slick, the work stands out as a refreshing example of healthy earthiness.

Now in its 11th year, Frieze London 2013 (Oct. 17-20) hosts some 152 exhibitors, attesting to the fair's status in the global art market. Exhibitors represent 30 countries, making this year, according to the organizers, the fair's most international outing yet. Frieze Masters (also Oct. 17-20) has 130 exhibitors from 15 territories.

Countless satellite fairs like Moving Image and (new this year) Strarta have sprung up, and London galleries schedule exhibitions of their biggest hitters to coincide with the fair's opening; see Damien Hirst and Félix González-Torres at Blain Southern. At the preview, all the familiar faces from the art establishment were present: museum directors like Nicholas Penny (National Gallery), Ralph Rugoff (Hayward) and Nicholas Serota (Tate), as are artists like Grayson Perry, Anish Kapoor and Martin Creed.

If Frieze truly is nothing more than a temple of consumerism at its most devout, then the altarpiece is Jeff Koons's bronze megaliths of lobsters, kittens and candies, showing at Gagosian Gallery. The rumored $10 million price tag (which the gallery declined to confirm) reinforces the notion that cash is king. Yet only a booth away, at Berlin's Esther Schipper, Pierre Huyghe's aquarium works house horseshoe and arrow crabs—this living ecosystem is utterly unconcerned with cash flow. Even if his aquarium pieces do come with a price tag of $165,000 each and a life span of 15 years, here "prehistoric life forms that pre-date all this," as a gallery representative describes it, are top of the food chain.

Still, the chief traffic is buyers. Dealers in the Frame section, reserved for 18 galleries founded post-2003 (16 of whom are Frieze first-timers) all told A.i.A. that sales were good. There are some lively examples here, like Berlin-based artist Ryan Siegan-Smith's works concerning memory and mnemonic techniques in a mixture of video, installation and drawing at Malmö's Johan Berggren. Seemingly everyone's favorite were Marlie Mul's sand and resin puddles at Milan's Fluxia, for about $5,500.

In the main exhibitors section, Laura Bartlett is returning for her fifth year with a sampler of artists including Cyprien Galliard, Nina Beir, Ian Law and Allison Katz. "Art fairs are where the relationship between gallerist and artist is both least and most romantic," the London dealer told A.i.A., "but underlying everything is the same yearning, seeking out treasure."

No one is forthcoming about what they are selling, for how much and to whom, but A.i.A. did overhear one dealer comparing shopping styles. "The Europeans walk round for days writing notes, then do all their buying on the Sunday. If the Americans want it, they buy on the spot." One pair of arty spectacles with a New York City rasp dropped $80,000 on two Warhol drawings at New York's Cheim & Read with the comment, "I just came off my medication this morning!"

On the whole, the air is less frenzied than past years. Air kisses have given way to a more serious crowd. Combined tickets to Frieze London and Frieze Masters are $80 this year, so it is less about networking and more about cold, hard currency. "The market has matured," an English collector told A.i.A., "and people are here to do business."

That includes the crowd at Frieze Masters. Now in its second year, Frieze Masters provides a greatest hits of everything up until 2000. If modern art has been knocked off its perch by the growing strength of the contemporary market in recent years, then Frieze Masters addresses that balance. Dealers bring out prestige works of Japanese Gutai and Russian Constructivism.

Most galleries at Frieze Masters are returning exhibitors, but some pulled out, deciding to concentrate on the main fair and its reputation for guaranteed sales. "We did both fairs last year, and did well at Frieze but we didn't make any money here" at Frieze Masters, Elliott MacDonald, representing Pace, told A.i.A. "But when you don't do a fair, you always have the sneaking suspicion you are missing out."

MacDonald's suspicions may be right. Walking into Cheim & Read, one of the dealers says loudly on speakerphone, "I can't tell you exactly what but a very nice thing happened today." One museum director (who wished to be unnamed) put a reserve on the entire exhibition documenting artist Rose English's feminist dressage performances at London's Karsten Schubert. 

There are no bargains at Frieze Masters. Sam Fogg, a London specialist in medieval art, has maybe the most beautiful object in the entire fair: an illuminated manuscript from the Book of Kings, selling for $8 million. New York-based Hans P. Kraus Jr. has a Julia Margaret Cameron album for about $7 million; portrait subjects include Darwin and Tennyson. Then there is The Census at Bethlehem by Brueghel the Elder, which hasn't been on the market since it was bought directly from the studio 400 years ago by an English family who has kept it in Kenya in recent years.

Frieze Masters contextualizes Frieze London in a way the organizers probably never intended. It backs up contemporary works as often as it tears them down. Korean artist Kyungah Ham is showing an embroidered canvas at Kukje Gallery (Seoul), a clear homage to Alighiero Boetti (showing at London's Dickinson as part of Frieze Masters). But when quizzed, the exhibitor told A.i.A., "No. Not like Boetti. Original." On the flip side, the three Michelangelo Pistoletto works on sale by different galleries at Frieze Masters are called out by Gavin Turk's Pistoletto's Waste (2013) at Vienna's Galerie Krinzinger at Frieze London. Turk's work mimics the originals' mirrored stainless steel, but replaces the boy and dog pictured in Pistoletto's series with an image of black trash can liners. 

Where inclusion in Frieze once meant you had made it, Frieze Masters makes the main fair look increasingly like level one in a long-drawn-out strategy game, with the question now being: How many of the works showing at Frieze London will make it into Frieze Masters in 10 years' time?