BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

Tenants in Brooklyn tend to stay a minimum of 4-5 years in NYC due to high costs of moving.  

I highly recommend going to meetups and talking to investors in person. 

Should I price the land 2 times above market value and offer a low interest rateORPrice the land at current market and use a very high rate?

And you get feedback at a level high enough to determine how to proceed. 

The high end rental properties can be a different animal than your run of the mill $2,500 month rental both in terms of upkeep and demand.

that we’ve learned in our 24 years, managing almost 700 doors across the Metro Detroit area, including almost 100 S8 leases:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

I don't do this for a living and have no real world experience, but at 40% down, even with a 7% int rate, that seems like a high monthly payment.

And in these circumstances the chance of the buyer being sued for a default is rather high.  

If you are new to the business the most common issue is you're either locking up deals too high or you aren't finding attractive deals.