Quote from @Cathy Li: It's a white label software built on go high level.

If this $30k was instead invested in a taxable brokerage account, you'd pay capital gains taxes on the $70k of growth and be left with a tax bill as high as $14k.

Ask yourself: do I really have the knowledge of real estate principles, real estate law and real estate finance; the network of contacts; the experience both in business in general and real estate in particular; the time available; and the analytical ability to compete against FULL TIME EXPERIENCED PROFESSIONALS to be successful in a field where the failure rate is so astronomically high?  

Talk to your attorney, and if you dont have one, get one - as @Ken M. said, this is highly specific to the state and the circumstances.

(Assuming quality of service doesn’t decrease.)No matter how you look at it, that is a ton of money.

He offered to sell it to me with owner financing for $400,000 and only required 10% down, so I jumped on it.

Instead of jumping into an expensive Long Island market with negative cash flow, consider investing in a Texas market like San Antonio, Houston, or DFW suburbs—these areas offer strong rental demand, lower property taxes than NY, and better cash flow potential.

So, we have to "hope" they have a very high integrity level.

If you ask them to write an offer, don't disappear for weeks at a time after you make the offer. 

Denton County offers opportunities in suburban and college town markets, while Grayson County provides affordable entry points with cash-flow potential.