Any New York City property owners can give me advice?

[William M.]

I'm looking to start off my real estate adventure with my first primary home. You may tell me I need to educate myself or think realistic. But this thought came of dreaming big. I sort of have a little knowledge, but I'm trying to get a little advice. My goal for my primary home because of the area I want to move in there are mostly two families for sale. These areas though have R3-2 and R4 zoning. Maybe you can school me on R3-2, but for now my primary focus is R4's. Would it be possible to build a four family with each unit on different floors not including the basement. Is there a way to get a general idea on to how much it would cost to convert a two family to a four family. And what would be the procedures to making this happen. Would making these additions bring up the home value. On a $625,000 budget what would be a good purchase price to leave room for construction costs. Finally is this a good idea. Any feedback would be appreciated.