I would say it is valid advice no matter where you are at in your business.

now back out 600 for rent back out 200 for utls cable etc. back that leaves your tenant with 1000 a month before any tax's taken out.. to pay for car  gas  insurance clothing food kiddos dog dog food.etc etc.. you can see why the 600 dollar renter by and large is one flat tire from missing rent.. or say Christmas comes around.. now lets take the 1200 dollar renter run the same math.. 3X  3600 a month to qualify.. 1400 for rent and utls. leaves 2,200 a month to live on etc.. or double the stability.. this is why the risk is so high.. 

It would be a "condo-style" duplex where one unit is on top of the other.To convert it, I would need to install water, electric, and gas meter, wondering if anyone knows how much those would cost? 

There is no such thing (USA) as a clever attorney getting the LLC set aside or a judge legally setting the protection aside without valid reasons.

If the seller really wants to sell, the written, signed agreement will be legally valid and you could sue if they break the agreement.

You need to find valid comp sales to show lower value than yours.

Then you might just do a quick consultation with a land/zoning attorney, again to get a feel for how big of a battle it would be and your chances of success.It's also worth mentioning that, while rare, very occasionally you can sometimes research a property in the Providence City Archives (5th floor of city hall, walk up) and find a # of units documented, prior to the adoption of the current zoning code, and have a valid argument for a pre-existing, should-be-grandfathered number of legal units.I've only done that on one property, researched it in the City Archives to try to find a greater # of legal units in the early 1900s from Census / City Directory records.

And that if I wanted to move the profit from a residential building lot, with no home on it, to a finished or under construction home, that I would it would not fit the like-like rule.However, I just got off the phone with the person who helped me with the last 1031 I did, and she indicated that as long as it was real property, purchased for investment only, that I could use that as a valid 1031. 

If you are only planning on buying one property in the relatively short term, then this is a valid request, even if you guarantee them something small, say a few hundred dollars.

@Wayne Brooks, But inactive or active, a valid RE license is still a valid RE license.