Tracy Sparks moved up. And then some.

Having sold her 1,800-square-foot cottage on the North Side's landmark Alta Vista Terrace--the house was on the market only half an hour, she said--Sparks decided she wanted more space and more "personalization" in her residence.

Sparks, 39, a financial consultant, found what she wanted in a new single-family home about a block north of the Cabrini-Green public housing development, where for more than $1 million she more than doubled her space and got a back yard. She also customized with high-end fixtures and cabinetry and put in such special-use spaces as an art room.

"In this market, you want quality things. You want things that are unique and personal to you because your home is important to you," she said. "It's not only an investment, it's an investment that you choose to live in."

Welcome to Chicago's million-dollar real estate market, where size always matters and where some new players are changing how and where the game is played.

Real estate observers said the Chicago market probably has less velocity than some other million-dollar-mad areas, citing San Francisco--a perennial--and some areas of Atlanta and such resort areas as Kiawah Island, S.C. But, it's nonetheless steady and healthy--with some interesting twists.

At the high end of the market, Chicago real estate agents and builders said they're seeing buyers with some new profiles, who have surprised them in where they choose to move and, in some cases, the ardor with which they go about doing it.

For one thing, many of them are younger than they used to be, some of them even in their 20s.

Fueled by robust investments and entrepreneurial success, they're stepping up and buying showplace homes.

"In this market, your younger buyer has been out en masse because of the lower interest rates," said James Kinney, president of the Rubloff Residential real estate firm.

"Everybody is starting out way up there," said Rita Starkey, an agent with Re/Max South Suburban in Flossmoor who is marketing a $2.5 million house that comes with 46 wooded acres, four lakes and a horse stable.

Starkey said that although million-dollar-plus activity is fairly uncommon in her area, she nonetheless sees younger buyers confidently purchasing at much higher prices than just a few years ago.

Carrying perhaps even more purchasing clout, though, are empty-nester couples, many of whom are leading the widely reported charge from suburbs to expansive condominiums and town houses in the city. Other empty-nesters are not moving nearly so far, choosing instead to go for the mansions they've long dreamed of, just blocks from the places they've long called home.

Experts said that, in general, such pricey homes are not a quick sell and never have been. But there are some startling exceptions.

"What's interesting to me is the average market time," said Rubloff's Kinney, whose firm specializes in downtown and North Side properties. "Last year, the average market time was 122 days. This year it's 67 days. What we're seeing across the board is people are making decisions quickly to buy now or lose. They're feeling they have to jump on it."

The bidding wars over million-dollar houses probably are limited now to the city, local real estate experts said, but the activity in that bracket, across the board, is undeniable.

In metropolitan regions across the country, the percentage of homes sold at $1 million and up more than doubled from 1993 to 1998, according to First American Real Estate Solutions, a California firm that gathers housing data.

The median price of an existing single-family home in the Chicago metropolitan area was $166,800 in 1998, according to the NAR.

Some segments of the market may have peaked, observers said.

Residential Planning Corp. of Hoffman Estates, Ill., tracks home-building statistics, and finds that 1999 starts have declined from last year's at subdivisions with houses priced at $1 million. On the other hand, it also reports that the Chicago area has 78 subdivisions that are priced pretty much exclusively in that bracket.

Even if Chicago area sales have been fairly steady for several years, experienced real estate agents said they're surprised by the actual numbers. For example, on July 12 the Multiple Listing Service of Northern Illinois, which covers the metro Chicago region, offered no fewer than 569 single-family residences priced at $1 million and up. These don't include condos, for-sale-by-owner homes and projects of many custom builders who don't work with the MLS.

In the condominium area, most of the upscale action is downtown, and Kinney said a significant percentage of million-dollar "pending sales" are signed contracts for units in buildings that haven't even been constructed yet. Part of their allure, he said, is the developers' willingness to cater to wealthy customers who want customization.

The downtown, upscale buyers are not exclusively ex-suburbanites. And apparently they're more broad-minded about where they want to plunk down their million-plus.

"We're finding that all of the old, preconceived ideas of 'acceptable areas' have really gone away," Kinney said. "The buyers will say, 'Let's look at Bucktown, let's look at Taylor Street. These newer buyers don't have neighborhood prejudices.

"If they can get the bigger lot by going to a fringe neighborhood, they don't have the fear of plunking down the million to build the house."

Roger Luri's company, Metro Homes, built Tracy Sparks' house near Cabrini-Green and is building several other similarly priced ones in the same neighborhood. What do you get for a million dollars these days? Luri said one thing that draws his buyers is the promise of four to six bedrooms, even though most don't have kids. He also said that brand names mean a lot to these buyers, so standard among the inclusions are Viking ranges, Sub-Zero refrigerators, Grohe faucets and Kohler whirlpool tubs.

Scott Sevon, who builds custom homes mostly in northern and northwest suburbs, adds a few items that are frequent features these days: "For one thing, larger garages--no, mega-garages--with an average of four or maybe six bays.

"They want stairways that lead from the garage into the lower level. Everyone wants an 'English' or walkout basement. They're doing fancy libraries and exercise rooms. Home theaters are very prevalent.

"There is a tremendous influx in elaborate lighting. We're building homes with 'safe rooms' and hidden areas" to protect the residents in case of a home invasion.

North Shore architect Page agrees that his buyers want the finest finishes and amenities, but there's one other must-have amenity: "They want land. They want as much of it as they can get.

"You won't get an acre in Winnetka for under a million, that's for sure. I have had people who have paid a million and a half" for a teardown.

But like everything else, money isn't what it used to be, to a degree. For one thing, there's that appreciation factor. And then, well, there are just some changing expectations out there.

"I'd have to say that a few years back, if you bought a property for a million, you didn't say that you missed much," said Rubloff's Kinney. "Today, you get high finishes and you get some spaciousness, but your million-dollar buyer is still walking away, saying, 'I wish I had this' and 'I wish I had that.' "