I recently wrote a piece about a downtown high-rise condominium project, with units ranging from $500,000 on the bottom floors to more than $13 million for the penthouse on the thirty-third.

I received only one e-mail in response, and that was from a woman who lived in a single-house, in an inner-ring suburb that had seen better days.

"How can people pay $500,000 for a first-floor unit, that seems to have no view?" she asked. "I mean, that's half a million dollars for NOTHING."

The note was funny in that this woman, had paid $50,000 for a view of a house almost exactly like hers across the street, and thought nothing of it. I could have argued that both the construction, and the price said something positive about downtown developments everywhere in the United States, but I chose instead to thank her for her observation and left it at that.

Had I had this piece of information from RTKL, the architecture and planning firm, when she wrote to me, it might have shown her another way of thinking. I didn't, however, so I'll share it with you instead:

"While penthouses with all-encompassing city views used to be the biggest high-rise draw, the trend is shifting and residents are instead looking to streetscapes as the number-one amenity."

I will concede that condos on lower floors are selling faster than penthouses. While RTKL believes the reason is that advances in soundproofing technology have made street level units as quiet as penthouses, however, you and I know that the most likely answer is found in the relationship of demographics to price.

Downtown Dallas, downtown San Diego, downtown Denver, downtown Philadelphia and downtown Chicago are attracting two kinds of buyers. The first is the young, single professional or young couple; the second is the empty nester moving in from the suburbs. The chief attraction for both are the amenities that downtown living affords, along with the ability to socialize easily without having to drive miles by car, as you have to do in the suburbs.

The returning empty nesters comprise a much smaller percentage of downtown buyers. The larger percentage is the first-time, young single buyer, whose earning potential, by and large, will come much later, as they buy their first home. This means that you are more likely to see the majority of downtown condo buyers purchasing the less expensive units on the lower floors, than the more expensive units on the penthouse floor.

In a high-rise condominium, units increase in price the higher you climb, reaching the peak price at the penthouse. Those units tend also to increase in square footage and amenities on the higher floors.

A high-rise that was designed by New York architect Robert A.M. Stern, has fewer units per floor as it rises to 33 stories above the ground. That makes them expensive. The other thing that adds to the price is where they sit on those upper floors. If they are corner units, they have views on two sides, and the buyer pays for those views.

In addition, Stern has added expanded balconies -- more like deck-sized patios -- to the upper-floor units, so that the buyers can sit and enjoy the views that they are paying a premium for, away from the noise that height, not soundproofing, provides to outdoor living.

RTKL makes the point, and I will concede it, that the street-level units in cities such as Dallas and San Diego offer views "of beautifully revitalized downtown areas." I spent three Builders Shows in Dallas in the late 1990s, just as the condo conversion movement was getting underway, and was impressed with their Light Rail system as well as the renewed focus on downtown after 50 years of suburbanization.

San Diego's downtown redevelopment is a case study in genius, and that doesn't do it justice. But San Diego is in dire need of affordable housing, and only one-quarter of the population can afford to own a house there, so the fact that lower-floor units are going first is hardly a surprise.

RTKL also contends that the community amenities -- the pool/gym, internet café, and home theater -- also are being taken street side. Every high-rise builder I know is putting those things eight floors up from the street at the very least, to provide homeowners with both a sense of security and privacy.

There's something that hasn't been mentioned, but is a key ingredient of downtown living. Although most of these developing 24/7 downtowns are getting safer, most buyers, when asked, maintain that they feel safe as they go higher. There is also more privacy up there.

The bottom line: Where you buy depends on how much you can afford. If street level units are what you can afford, you aren't going to ask to see the penthouse.