Show him the evidence of the city code violations.

@Larry DIIHave you seen evidence that the place has been rehabbed?

The evidence portion is why many people hire an attorney.

If you are already rich you do not need an income and speculating on appreciation is simply a hobby.speculate[ˈspekyəˌlāt]VERBform a theory or conjecture about a subject without firm evidence: I have firm evidence. 

However, he comes from Florida and doesn't exactly have a wonderful reputation from his time in Florida at least according to this article: https://www.floridatrend.com/print/article/12331Per the article: "Bultema left a total of 81 homes incomplete, and prosecutors found enough evidence to charge him with criminal fraud in 16 of those cases, including the Simmonds'.

Unless you have real concrete evidence that you under-priced your home, I'm going with the majority here and saying you should ask for highest and best and accept whichever one that is.

You will need to prove something that you like we do not have the evidence to prove

Wait till the buyers claim they gave you personal property for payments, that they did work for payments or they sell the property.Dlay, delay, delay as they live there..... your buyer will probably play dumb with good evidence of that and paint you as some shister selling on a QCD as well.You could be in for a long ride on this mess up.

It doesnt hurt when you have the evidence of what you do with photos and closing statements. 3/2 1150sq ftClosed Sept 3/23/2016Rehab completed 5/23/16In Escrow 6/23/16Purchase 294kOriginal rehab budget 65KFinal Rehab cost 95k - the decision to increase the budget was critical to maximize the sale price of the home.

But that is not a requirement However, there can't be any concrete evidence that your intent from the beginning was to convert and move in.Once you change your intent, move in and convert it to your primary residence it now falls under sec 121 with some extra provisos.Once you have lived in it for 2 out of the previous 5 years and have owned it for at least 5 years you can sell and take a % of the gain tax free but prorated between the time used for rental (non-qualified use) and the time as primary residence (qualified use).