Time Machine Effect: 221 Clinton Avenue

If you had a time machine, would you exploit all your knowledge of the future and turn yourself into some sleazy mogul like Biff did?

Because some people really think they're living in the past. Last year, everyone lusted after the castle-like 287 Dekalb Avenue, but only one stepped up to the plate and took it down for $1.8M, closed in June 2011. And even that place needed new kitchens and baths. Now that the market's done a complete 180 since the final value days of late 2010 - early 2011, people still think they can use last year's prices to dictate this year's bids. A month after 287 Dekalb closed, Prudential listed 221 Clinton Avenue for $2.2M. Were they off a bit? Sure. But not by too much. After two price drops down to $1.95M, this stunning 4,700 sqft 2-Family closed last month for $1.87M.

Lose yourself in the "steep sloping mansard roof", "Corinthian colonnades", "ornate terra cotta enframements" of this "traditional Romanesque Revival/neo-Renaissance five story townhouse designed in 1891." Remember, Park Slope wasn't the only place building mansions 100+ years ago, people!

You don't get a true yard here on Clinton Ave, but there's a nice back deck to make up for it. And check out how quick they rolled a 1BR rental out the door for well over $2,000/month.

People who think they have a time machine will tell you, "Well, if 287 Dekalb closed for $1.8M, no way I'm paying more for 221 Clinton Avenue..." but that's simply not how it works - especially not in an up market. People love to get lost in comps, without realizing the first and most important thing about comps: they're long gone. 221 Clinton Avenue never ever competed with 287 Dekalb because they were never on the market at the same time. Can you imagine how much 287 Dekalb would list for if it came out now in this market? Another huge fact about comps that most people overlook is the fact that their contract price was negotiated months before the sales price was recorded. So a closing in June 2011 could be based on a price negotiated in February of 2011, which has little-to-no bearing on February 2012. But you don't have to be a mad scientist time traveler like Doc to know that.

Pro's: curb appeal, size, original details galore, great upkeep, back deck, another great mansion, better than spending $3M in the Slope

Con's: no back yard, a little bit of a hike to the trains, buyers living in the past can't wrap their heads around it

Ideally: Since you can't actually go in the past, you've gotta look to the future. And there are deals getting done today will look like steals in a few years.