You are not allowed to compound interest.If you bought the certificate from the state on a best price offer, you charge interest on your purchase price, not on the full amount of the taxes that were due, but were not paid by you when you purchased.After you obtained your tax deed, you are entitled to something called "mesne profits" if you file an ejectment lawsuit against the former owner and they redeem during that lawsuit.  

You could house hack by purchasing a small multifamily with an FHA or conventional loan, reducing your living expenses while building equity.

I wouldnt give any consideration to what the seller needs in order to break even in determining the purchase price.

Does the LLC legally own the property that was purchased? 

I currently own one property, and I’m planning to purchase another.

I live in NJ but am looking to purchase an investment property in NY State.   

We would prefer to jump into the market with a duplex, triplex or quad as our first purchase. 

Or buy something that needs some love and some hard money lenders will fund up to 90-100% of the purchase and rehab.

Here in Florida there are some opportunities to purchase a brand new home, cash flow, and minimize your capital expenditures for quite a while.

Here are the pros as i see it: easy (no purchase necessary, you know the property), likely prop 13 property tax discount, possibly below current rate loan.