A sudden proliferation of eight-digit penthouse listings in the last week is helping prove the strength and durability of downtown Chicago’s luxury microclimate. One year-topping offering is an anomaly, but the three priciest condos of 2014 going to market in a seven-day span demonstrates a new giddiness at the high end. It also gives a window into marketing strategy and competition for a tiny pool of qualified buyers.

“There are enough high prices now that buyers are getting used to seeing them,” says KoenigRubloff’s Janet Owen, representing not only the new highest-priced condo of the year at 189 East Lake Shore Drive but also the most expensive single-family home: 1955 North Burling Street.

The first place to list last week, a 12,506 square foot duplex at Lincoln Park 2550 selling for $13 million, won early press from yours truly. A second offering, at the Ritz-Carlton Residences at Michigan Avenue and Erie Street, just hit the market for $11.2 million. Both of these are the raw spaces. Their buyers will differ somewhat from the buyer of the triplex penthouse at 189 East Lake Shore Drive. “It can take upwards of $300 a square foot to build out an ultra-high-end space,” says Jane Shawkey, Coldwell Banker listing agent for the Ritz penthouse and many other units in this 30 percent-sold, 89-unit tower. “But you get absolute freedom to customize the only space like it in the downtown area.”

The release of the Ritz penthouse at this time has more to do with the building’s other full-floor space going under contract in 60 days. It’s the upstairs neighbor—the top floor—and is almost identical with 6,028 square feet of interior and 660 square feet of terrace (the other stat line reads 6,597 and 889). The last posted asking price was $10,850,400, and it had two local bidders racing to the finish line. The press release for the second penthouse touts the building’s location and in-house spoils, namely membership in the owners-only Landmark Club, which basically extends hotel services (gym, concierge, butler service, dry cleaning pick-up) to residents.

The final new listing is very much a finished masterpiece, measuring 7,662 square feet on three levels with another 3,000 square feet of intertwining terrace. The asking price is $15.5 million. “I love that those raw spaces are on the market,” says Owen. “Because it makes mine look so good.” This wasn’t, however, the intention of Owen or her sellers. “Quite frankly, it’s pure coincidence. I caution myself not to follow what other brokers and developers might be doing. We waited for our photos and listing materials to be ready. There wasn’t a strategy otherwise.”

This property doesn’t need the promotional muscle of a major developer or specialized division of a big brokerage, not when it crowns The Mayfair, one of the city’s most recognizable buildings at the bend in the lake by Oak Street Beach and the only condo building on East LSD. Maybe you’ve seen the greenery dotting the roof—that’s the penthouse garden, with a solarium, pergola and a water feature, proven to accommodate parties of more than 100. Stepping down into the grand home are two more terraces off the great room and master suite. Opulent traditional finishes with walls clad in the priciest mahogany, chevron patterned floors, and, yep, an antique bronze entry gate, reflect the building’s 1924 classical revival architecture and 14-foot ceilings free up the space for art and lake breezes.

Prices for this and the Ritz space are set at roughly $1,700 and $2,000 a square foot, respectively. Building out the former will bring costs almost exactly in line. The real savings is further north at Lincoln Park 2550, where the 12,506 square foot duplex penthouse is on the market for $13 million or about $1,040 a square foot. Views from this perch are tremendous, and the ceiling and window dimensions are completely bananas. The primary drawback is the scarcity of outdoor space, with a handful of slim balconies totaling about 300 square feet. Click over to my account from a week ago for more details.

The drivers of this kind of real estate are out of sight and out of mind for the vast majority of us, and these dealings have scant impact on the equity the average Chicagoan hopes to secure. But this high-end activity does tell us to expect more polarization in the market, and the continued climb of prices for anything in the Near North Side’s orbit.