This seems to be a "fake" listing. The person advertising and representing this property is most likely a broker. They want people to call, only to explain the apartment is no longer available and try to convince you to be their broker.
I suggest contacting a Mortage Broker to get pre-qualified, first. If you do not have one, I can suggest a couple I have worked with in the past. Once you're pre-qualified, you'll have a better idea of where to begin your search. This is why a broker is so important. I will not wate you time with smoke and mirrors.
If you have any further question, please do not hesitate to ask.
Others have speculated as to what could be wrong, it could even be a clerical error in the database.
Your best path is to ask a real estate agent ("broker") to help you find an apartment in your price range.
The vast majority of NYC apartment sales involve two brokers--one for the seller and one who represents the best interests of the buyer. I work as a buyer's agent (not all agents do). There's no need for the buyer to pay the broker, because by prior agreement sellers brokers share commissions with buyers brokers.
Licensed Real Estate Salesperson
New York, NY
646 593 7207
Listen to Elena!
If it's a RealtyTrac "listing" it's probably not even for sale.......they simply compile data for homes/apartments that are behind in payments.............and then make you pay to see their lists.....$429,821 might be the amount that is owed........NOT a list price.