Breaking a New Construction Closing Contract

They will probably tell you to f'off, and then you need your lawyer. Ask him/her what rights you have to break the deal and when. If construction is long-delayed, you may have an out in the contract. If your lawyer let you sign an open-ended contract, get a new lawyer.

what price you bought it for? it is the most important factor to determine your next move

When you buy a new car, the resale value of it drops the moment you drive it off the lot. Yet, you buy it with that knowledge, and you drive away with the vehicle you'll use for the next X years. I made a number of equity investments in early March, some of which the value has dropped by 10-15%. Yet, my horizon for ownership is long-term -- 15+ years, so I don't mind the short-term drop -- I bought at a better price than I could have earlier, got in at an acceptable price for my long-term view, and am moving on to other concerns.

If you're buying with a view to the long-term, the short term dip should not be a concern. (I will ignore the 'but you could invest in Z and do better over the same term' argument, because all these big ticket purchases should be considered part of an overall financial portfolio, each with their own measures of utility and value).

The issue is: will the unit fall more in the short term than what the loss of deposit will be (taking into consideration some of it may be recoverable). Especially if this isn't the purchaser's dream apartment, or a long term hold. People always talk about "if you live in the apartment more than 10 years" but with 1 br apartments I'm seeing people's timelines (without market pressure) being shorter than that.

I will freely admit to be a long-termer: I was in my prior apartment 25 years. Maybe it's genetic: the house I grew up in had been passed down through 4 generations. Last recorded mortgage on that place was back in the 1940s (a HELOC, though they didn't call them that back then).

And there is nothing wrong with that (I was in my last apartment for 22 years). But if you look at how long most people hang on the 1 br units in the recent past I'm not sure giving advice based on the assumption of a long term hold is fitting.

That's why I noted that my view was based on a bias toward the long-term. The OP provided no indication of his time horizon, but was making an assumption that an immediate drop in valuation is worth breaking a contract over. My 'advice' is simply to point out that it may not be.

Whats the value of 1 bedroom in the future?
If more and more people start working from home, they'll want a minimum 1 bed plus office.
Something to think about.

Its very hard to walk away from money but it really does depend on what the math actually is.
If the market is truly going to drop 20%, it may be better lose the deposit and buy the new place. And maybe you dont have to lose the whole 10%. Tell them give you back half the deposit and you wont sue.

Things will rebound like they always do though.
I remember after 9/11 nobody wanted to live downtown.
Price p sq ft was half everywhere else, like $300/$400 p sq ft in today's primo tribeca.
Bounced back in less than 2 years.