Ask for 3 years PnL (profit and loss) for the building, as well as rent rolls. give yourself at least 30 days due diligence after they deliver the info to you. 

The cumulative effects of paying tax on your profits every year is underestimated by most — we're talking tens if not hundreds of thousands of dollars for even a modest investor over 30 years or so — and being able to defer those taxes for decades so as to reinvest all profits will be a boon to your net worth and financial position.Also, be wary of "flipping," per se, in your Solo 401(k) as you could come under the purview of the UBTI rules, with the result that you would have to pay tax, and the whole point of investing through a 401(k) is to defer tax. 

You should keep track of income and expenses to put together a profit and loss statement, which will ultimately go onto the schedule E (rents and royalty). 

I have one in Oregon that is just under 10 million and typical hard money rates are being quoted.. however frankly if you still cant make nice profit paying for HML or private money then the deal is probably to tight. if your talking 10 points and 20% then ya that would  be a little bit high.but 2 to 5 and 10 to 14 is in the all park.. for a HIGH risk horizontal loan.I just did one personally ( i was the lender) in Orlando and we were up there on the top end of what i am talking bout 30% apr  but the developer snag a great deal and will still make a few million on it while paying me 100k for a 700k loan he used for 7 months.. that seemed fair all around..

I think it's a fantastic idea and will be profitable for me given what I paid for the other place.

The difference would be my ''pre-tax'' (before tax) profit.

You can simply funnel off profits or invest time and money to improve since you control everything.You can choose to invest in anything from a trailer park to a residential community.

The cost of the insurance made the building not profitable, so I skipped insurance!

Then when you sell the property you will sell it as a Cost of Goods sold,  (General Journal Entry) which will deduct your expenses from the sale of the house, lowering the profit made from that house,For Example:Let's say you purchased a house for $35,000.00 and you fixed it up and the total amount of money you spent to fix it up was $7,000.00. 

My back ground is in church and non-profit work, but one year ago (March '17) I got into slingin' mortgages.I'm highly analytical and I'm addicted to spreadsheets.