Pay down debt, budget/cut expenses, increase income, and finally save/invest.

.$2,135.00MONTHLY INCOME$1,694.08MONTHLY EXPENSES$440.92MONTHLY CASHFLOW14.08%PRO FORMA CAP$9,853.40NOI$22,125.00TOTAL CASH NEEDED23.91%CASH ON CASH ROI13.59%PURCHASE CAP RATEExpensesIncome50% RuleTotal operating expenses:Mortgage expenses:Vacancy:$170.80Repairs:$213.50CapEx:$106.75Electricity:$50.00Water & Sewer:$162.00Insurance:$120.00Management:$213.50P&I:$380.20Property Taxes:$277.33$72,500PURCHASE PRICEPurchase Closing Costs$2,000.00Estimated Repairs$2,000.00Total Project Cost$76,500.00After Repair Value$70,000.00 Down Payment$18,125.00Loan Amount$54,375.00Loan Points$0.00Amortized Over30 yearsLoan Interest Rate7.500%Monthly P&I$380.20Total Cash Needed$22,125.00 Financial Info2.79%2% RULE $15,625.00TOTAL INITIAL EQUITY2.83GROSS RENT MULTIPLIER 2.16DEBT COVERAGE RATIOAnalysis Over Time3% /yearEXPENSE INCREASE 3% /yearINCOME INCREASE 2% /yearPROPERTY VALUE INCREASEYear 1Year 2Year 5Year 10Year 15Year 20Year 30Total Annual Income$25,620.00$26,388.60$28,835.54$33,428.29$38,752.55$44,924.83$60,375.21Total Annual ExpensesOperating ExpensesMortgage Payment$20,328.97$15,766.60$4,562.37$20,801.97$16,239.60$4,562.37$22,307.82$17,745.45$4,562.37$25,134.21$20,571.84$4,562.37$28,410.77$23,848.40$4,562.37$32,209.20$27,646.83$4,562.37$41,717.40$37,155.03$4,562.37Total Annual Cashflow$5,291.03$5,586.63$6,527.71$8,294.08$10,341.78$12,715.62$18,657.81Cash on Cash ROI23.91%25.25%29.50%37.49%46.74%57.47%84.33%Property Value$71,400.00$72,828.00$77,285.66$85,329.61$94,210.78$104,016.32$126,795.31Equity$17,526.25$19,494.41$25,837.43$38,134.84$53,197.53$71,986.64$126,795.31Loan Balance$53,873.75$53,333.59$51,448.23$47,194.77$41,013.25$32,029.67$0.00Total Profit if Sold *-$1,449.73$6,062.22$30,895.02$80,784.39$143,073.13$220,258.21$432,774.81Annualized Total Return-6.55%12.87%19.10%16.62%14.34%12.71%10.60%

If not, you may need to increase the septic to handle two family, per your county health dept codes.

However this can result in extra fees hence increasing money to the City.  

@John Woodrich"Equity doesn't kill cash flow, equity increases cash flow."

Your expenses after taxes remain the same as well so you can save $160 per month (until your real estate property taxes and insurance increase). 

Does it make sense to increase my home debt to invest in other property???

Knowing that, if I did buy the property, I may slightly increase rents at renewal time.

. $100k under the county appraisal is not to low - just work with your numbers. you can put it on paper with 30 working days Due Diligence clause and option to increase it by another 21 days. 

It's full of dings, dents, scratches (I live in South Philly, nothing but street parking), missing a hub cap, and its in "crap gold" color.