If the answer is yes, then it's a no brainer to make minimum payments on your 2.8% interest rate mortgage, and use the funds that you would have paid extra to pay it down faster, to either invest in more real estate, the market, or anywhere else where you can get a ROI > 2.8%.If the answer is no, then feel free to aggressively pay it down as fast as possible, to become debt-free faster, and just have a large amount of money in savings or to splurge with.The bottom line is that your 2.8% mortgage is GOOD debt.

@Jacob HavlovickBigger Pockets is a great place to find a real estate tax accountant.A good real estate accountant can save you thousands of dollars by leveraging entity selection and formation, tax deductions, cost segregations, bonus depreciation and tax planning.I recommend finding an accountant who specializes in real estate taxation, business taxation, financial planning and tax planning.You may want to consider working with your accountant remotely to expand your options.I would also recommend looking for a accountant willing to work with you throughout the year.

She has some stock (maybe 50k), some retirement IRA of around 100k which I believe she has started to take and then maybe 20k in her savings account.

When you go to sell, Montvale requires a certificate of occupancy so this issue has to be resolved in advance of a sale.Although I am not a lender, I assume you will not be approved for an owner-occupied mortgage on 5-units if it is a legal 4-unit without some type of mortgage fraud whether in reported rents, units, or another legal document or representation (very very large issue from a legal perspective with multiple arrests in the last year for anyone playing fast and loose).As far as the DCA, I would recommend coordinating your work with the city with the DCA.

Fast forward 20 years: I now have money in the bank, excellent credit, live modestly on my own, and run a business that’s doing well.Unfortunately, I wasn’t able to save much for retirement during most of my life.

By and large, QI's have very high ethical standards, and are sometimes overlooked as the engines of this tax saving tactic.]REPUTATION MARKERS 📊INDUSTRY STANDINGMembership in professional organizationsLeadership roles in FEAEducational contributions to the industryRelationships with major title companiesCLIENT RELATIONSHIPS 👥Testimonials from CPAs and attorneysReferences from title companiesLong-term client relationshipsTransparent fee structuresRELATIONSHIP RED FLAGS 🚩Overly familiar with your realtor/brokerKickback arrangements (illegal!)

He has been saving his money for years and has plenty of money saved but no experience with real estate investing.

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).

I'd been working and saving for many years, however, did not feel it was enough.

For less risk, consider hard money or a business LOC.Remember that LLC might help in tax savings if you are going to have decent profit.