I kept looking at my market and saw a 6bd 2 unit for sale at 55k.

I know that the Zillow estimate isn't going to be 100% correct, but based on what the first floor looked like, the sales price of other two flats in the area and my own knowledge of the area, I now feel like we should have either offered quite a bit less or walked away.

We will subsequently split the cash flow 50/50 each month, and if/when we decide to sell it, the profit from the sale will first go to allow me to get my remaining invested capital back, and then we would split 50/50 the profit after that.So, I have 2 questions -1.

Also, we know that there is a low supply of houses for sale.

The seller signs a Purchase and Sales Ageement The buyer signs the Assignment contract.

He is based in Somerset County and is helping me through a sale (about to close) in New Brunswick. 

You might also look into a Monetized Installment Sale to rescue a failing exchange.

Or should I wait for their lease option to expire and then proceed to put it under contract with a normal purchase/sale agreement.

Also,  The fact that the sale price double from last year, does not necessarily mean that the taxes will double. 

Seller property had patio and Jacuzzi permit but during the sale process utility lines  was found and cause title issues.