I bought the property for 120k and each was sold for about $30k and not sure if I should divide the original purchase price and subdivision cost by 7, or just lump it all into 1.

Currently it is being sold as a one single lot. 

You'll want to review the HOA's CCRs ... you likely received a copy of these docs before purchasing.

Hello, I am wondering if a seller of an existing property, say a 4 plex, can do a 1031 into a 'new' property with the same person or entity that he sold the 'old' property to? 

The reason I did not take that into account because the property was sold to state for taxes over ten years ago.

For those that closed, I looked up what they eventually sold for.

I built the new homes across the street in the last two years.first one I built sold for 450k  last year I sold the one next to it for 550k and this one I have on the market as you can see for 649k.. 

I've sold 45-50 properties with seller financing and I've made good money on it.

I just sold a multifamily of mine in Chelsea and I think it went $50k over asking.

@GregDowney Can private lenders provide copies of closing statements or something to verify they are legit?