Just to be clear capex is large repairs like a replacing a roof/painting the building/unit remodels etc.

Of course it would be a dream to find one like this for $100,000, but those seem to be very rare occurrences.So you rent the expensive side, leave in the cheap side for $200-$300/month....not accounting for vacancy, repairs, reserves, leasing.   

Most of the housing stock is older so repairs and maintenance occur frequently unless the house has received recent upgrades.

in the end, I will spend 25% more to repair his “finished work!”

Looking at the numbers CAPEX and repairs add a huge amount to the monthly expenses.For instance, this third deal:Monthly Income: $1,100Monthly Expenses $1,134.14Monthly Cashflow: -$34.14Pro Forma Cap: 5.22%NOI: $5,215Total Cash Needed: $11,050Cash on Cash ROI: -3.71%Purchase Cap Rate: $5.73Sale Price: $91,000Closing Costs: $2,500Renovation Costs: $4,550 (5%)TOTAL PROJECT COSTS: $98,050Down Payment: $4,550 (5%)Loan Amount: $87,314.5Loan Points: $864.5 (1%)Amortized: 30 yearsInterest Rate: 5%P&I: 468.72Total Cash Needed: $11,050Property Taxes: $2,184/yr2% Rule: 1.13%Initial Equity: $12,685.50Gross Rent Multiplier: 6.89Debt Coverage Ratio: 0.93Expense Increase: 4%/yrIncome Increase: 5%/yrProperty Value Increase: 4%/yrCash on Cash ROI: YR1 (-3.71%) YR2 (-0.63%) YR5 (2.64%) YR10 (9.76%) YR15 (31.56%)Annualized Total Return: YR1 (2.48%) YR2 (22.27%) YR5 (26.37%) YR10 (26.47%) YR15 (22.20%)Total Profit if sold: YR1 ($274) YR2 ($5,469) YR5 ($11,251) YR10 ($24,701) YR15 ($70,982)Expenses:HOA: $82Insurance: $66Taxes: $182MTG: $468.72 (@5%)TOTAL: $798.72Vacancy: $110 (10%)CAPEX: $190/mo (~2.5%)Repairs & Maint: $380/mo (5%)TOTAL EXPENSES: $1,478.72These expenses are different than the $1,134.14 mentioned early on.

Don't forget to remind her there are expenses (taxes, insurance, repairs - new carpet etc) and vacancies so rents can't equal the payment.

How much do you typically budget each month for maintenance and repairs?

If it's a sure deal as in 70%-repairs and minus your wholesale fee is the sales price. you shouldn't have a problem.

Figure in 10% for vacancy’s, 10% for capex, 10% for repairs, 10% contingency.

Then he taught me how to make perfect repairs.